Check out the sungrazing comet that dove into our sun on April 12-13, 2025. Look in the bottom left of this image, inside the circle. The comet appears as a relatively bright and slow-moving dot, heading toward the sun, then suddenly fading away just before it enters the sun’s inner corona. Shortly afterwards, you’ll see a streak. That’s an energetic particle, probably a cosmic ray. See closeups of the comet and cosmic ray, below. Recent data suggest that over 5,000 sungrazing comets have been discovered, with most belonging to the Kreutz group, thought to be fragments from a larger comet that broke up long ago. Image via SDO and SOHO.
Closeup of the sungrazing comet, spied shortly before it appeared to disintegrate as it hit the sun’s inner corona. Note the head (the comet’s core) and the tail pointing away from the sun. Image via SDO and SOHO.Probably a cosmic ray. Not the comet! Note that the comet appears in multiple frames of the animation above, more than just 1 or 2. Cosmic rays appear brighter when they are farther away from the sun. They only appear in 1 or at most 2 frames of these sorts of images from SOHO. Their short-lived appearance is how scientists tell the difference between cosmic rays and sungrazing comets. And why having multiple images is important! Image via SDO and SOHO.
Bottom line: The sungrazing comet appears as a relatively bright and slow-moving dot, heading toward the sun, then suddenly fading away.
Check out the sungrazing comet that dove into our sun on April 12-13, 2025. Look in the bottom left of this image, inside the circle. The comet appears as a relatively bright and slow-moving dot, heading toward the sun, then suddenly fading away just before it enters the sun’s inner corona. Shortly afterwards, you’ll see a streak. That’s an energetic particle, probably a cosmic ray. See closeups of the comet and cosmic ray, below. Recent data suggest that over 5,000 sungrazing comets have been discovered, with most belonging to the Kreutz group, thought to be fragments from a larger comet that broke up long ago. Image via SDO and SOHO.
Closeup of the sungrazing comet, spied shortly before it appeared to disintegrate as it hit the sun’s inner corona. Note the head (the comet’s core) and the tail pointing away from the sun. Image via SDO and SOHO.Probably a cosmic ray. Not the comet! Note that the comet appears in multiple frames of the animation above, more than just 1 or 2. Cosmic rays appear brighter when they are farther away from the sun. They only appear in 1 or at most 2 frames of these sorts of images from SOHO. Their short-lived appearance is how scientists tell the difference between cosmic rays and sungrazing comets. And why having multiple images is important! Image via SDO and SOHO.
Bottom line: The sungrazing comet appears as a relatively bright and slow-moving dot, heading toward the sun, then suddenly fading away.
Venus passed between us and the sun on March 23. At that time, it moved from the evening sky to the morning sky. Now Venus is shining very brightly in the east before sunrise every morning. It’ll be at another greatest brilliancy on April 27, 2025, lying not far from 2 faint-and-hard-to-see planets Saturn and Mercury. Over the coming weeks, Venus will also be climbing farther from the eastern horizon before sunrise. It’ll reach its greatest distance from the sun on May 31-June 1, 2025. Chart via EarthSky.
Venus brightest? Not yet but almost
Venus is blazing in the morning sky now. You’ll see it easily in the east before sunrise. It lives up to its reputation of outshining all other objects in our sky, except the sun and moon. UFO reports are probably increasing! But you’ll know better. Venus recently passed between us and the sun. So it’s now nearing greatest brilliancy, when we’ll see it at its brightest in our sky for all of 2025. Venus will reach peak brilliancy on April 27. But start watching now! You can’t miss it.
The planets Saturn and Mercury will lie nearby, but lower on the horizon and they might be challenging to spot in the bright morning twilight.
Look for Venus in the sunrise direction on any clear morning now. It’s visible not just in a dark sky, but in bright morning twilight as well.
Need an exact measure? At greatest brilliancy on April 27, 2025, Venus will shine at magnitude -4.7. That’s super bright! It’ll reach this brightness at 17 UTC on April 27.
After late April 2025, Venus won’t appear this bright to us again in the morning sky until November 2026.
When does it happen?
Venus was at greatest brilliancy in the evening sky on February 14. Then, Venus sank toward the sunset as it raced toward its sweep between the Earth and sun – its inferior conjunction – on March 23, 2025.
Afterwards, this bright planet quickly emerged into the morning sky. Earth and Venus are constantly moving in their orbits around the sun. Venus moves faster, and its orbit is smaller than Earth’s orbit. So Venus “laps” Earth every so often. Venus comes to inferior conjunction about every 19.5 months, or roughly 584 days. When it does this, it always moved from our evening to our morning sky. And there are always two times of greatest brilliancy surrounding inferior conjunction, one in the evening, followed by one in the morning.
Venus’ greatest brilliancy always happens about a month before – and after – Venus reaches inferior conjunction. Its next inferior conjunction – when it’ll move to the morning sky – is October 2026.
Earth and Venus orbit the sun counterclockwise as seen from the north side of the solar system. Venus reaches its greatest eastern elongation in the evening sky about 72 days before inferior conjunction and its greatest western elongation in the morning sky about 72 days after inferior conjunction. Greatest illuminated extent for Venus comes midway between a greatest elongation and an inferior conjunction. Adapted from an image by Wmheric/ Wikimedia Commons (CC BY-SA 3.0).
Why does it happen?
Greatest brilliancy for Venus is a combination of two factors: illumination and disk size. Venus was at superior conjunction – on the opposite side of the sun from Earth – on June 4, 2024. At superior conjunction, when Venus is on the far side of the sun from us, it’s at full phase and its disk size is always small. It emerged in the evening twilight in late July 2024. Then its disk size increased as its phase decreased and it reached its greatest brilliancy in the evening sky on Valentine’s Day, February 14, 2025.
Now at greatest brilliancy in the morning sky, we’re not seeing a fully illuminated Venus. Instead, as seen through telescopes – as Venus races away from Earth – its phase has been increasing, like a waxing crescent moon. Meanwhile, again as seen through telescopes, the disk size of Venus has been decreasing as the planet races ahead of Earth in orbit around the sun.
View at EarthSky Community Photos. | P Govardhana Siddartha of India submitted this composite of Venus taken over 4 month. Venus was recorded from December 2024 to March 2025 as it raced toward inferior conjunction in March. You can see how the size of Venus increased and the phase decreased during that time. Thank you, P Govardhana!
It’s a combination of phase and size
Greatest illuminated extent. It’s only when we see Venus as a crescent that this world comes close enough to us to exhibit its greatest illuminated extent, at which time its daytime side covers the greatest area of sky. And that means that Venus is brighter around now than at any other time during its approximate 7-month reign in the morning sky.
Disk size. Remember, again as seen through a telescope, the disk of Venus decreases after inferior conjunction. In July, 2024, Venus was around a 10-arcsecond gibbous disk through telescopes. At its greatest brilliancy in the February evening sky, Venus was around a 40-arcsecond crescent disk. Now at its greatest brilliancy in the morning sky on April 27, its disk size will be 40.7-arcseconds.
So greatest brilliancy for Venus is a combination of maximum phase and disk size. The two combine to give us a bright planet Venus.
Then, as it races away from us, the phase continues to increase … but the disk size decreases. So Venus will start to appear a smidgeon fainter to us following April 27, and fainter still (but still very bright!) until it slips away in in the sun’s glare in November 2025.
The phases of Venus – and its locations at inferior and superior conjunction – as viewed from Earth. Adapted from an image by NASA/ Chmee2/ Wikimedia Commons (CC BY-SA 3.0).
Venus charts for 2025, from Guy Ottewell
Venus’s greatest morning elongation in 2025 from the Northern Hemisphere as viewed through a powerful telescope. The planet images are at the 1st, 11th, and 21st of each month. Dots show the actual positions of Venus every day. Chart via Guy Ottewell’s 2025 Astronomical Calendar. Used with permission.Venus’s greatest morning elongation in 2025 from the Southern Hemisphere as viewed through a powerful telescope. The planet images are at the 1st, 11th, and 21st of each month. Dots show the actual positions of Venus every day. Chart via Guy Ottewell’s 2025 Astronomical Calendar. Used with permission.
Venus photos from our community
View at EarthSky Community Photos. | Eliot Herman of Arizona, submitted thisi photo on February 17, 2025, and wrote: “Venus at -4.87 magnitude and 43.1 arcseconds diameter. This is about the maximum brightness of Venus for 2025 evening planet.” Thank you, Eliot!View at EarthSky Community Photos. | EarthSky’s Deborah Byrd caught Venus with an iPhone, over the desert west of Santa Fe, New Mexico, on September 14, 2023. It was super bright! It’s easy to see, even from cities.View at EarthSky Community Photos. | Vedant Pandey wrote: “I am Vedant Pandey, a 17-year-old amateur astrophotographer from Varanasi, Uttar Pradesh, India. I photographed Venus since it appeared in the evening sky in February 2023. And here are the phases of Venus, from waxing gibbous in February to its crescent phase in August, as seen by my telescope.” Wow! Thank you, Vedant!
More Venus images
View at EarthSky Community Photos. | Roberto Ortu of Cabras, Sardinia, Italy, captured these images of Venus and wrote: “This is a mosaic with the best photos of the planet that I got from May 23, 2023, until August 8, 2023. The images show its phases, very similar to those of the moon, and the increase in its apparent diameter caused by the approach to the Earth.” Thank you, Roberto!View larger. | This composite image shows how Venus changes in size and phases as it gets closer to Earth. Image via Tom and Jane Wildoner/ Dark Side Observatory. Used with permission.This image of Venus was captured during daylight when Venus was 6% illuminated. Image via Tom and Jane Wildoner/ Dark Side Observatory. Used with permission.
Bottom line: Venus will be brightest in the morning sky around April 27, 2025. After that, Venus will next be at its brightest again – this time in the evening sky – in September 2026.
Venus passed between us and the sun on March 23. At that time, it moved from the evening sky to the morning sky. Now Venus is shining very brightly in the east before sunrise every morning. It’ll be at another greatest brilliancy on April 27, 2025, lying not far from 2 faint-and-hard-to-see planets Saturn and Mercury. Over the coming weeks, Venus will also be climbing farther from the eastern horizon before sunrise. It’ll reach its greatest distance from the sun on May 31-June 1, 2025. Chart via EarthSky.
Venus brightest? Not yet but almost
Venus is blazing in the morning sky now. You’ll see it easily in the east before sunrise. It lives up to its reputation of outshining all other objects in our sky, except the sun and moon. UFO reports are probably increasing! But you’ll know better. Venus recently passed between us and the sun. So it’s now nearing greatest brilliancy, when we’ll see it at its brightest in our sky for all of 2025. Venus will reach peak brilliancy on April 27. But start watching now! You can’t miss it.
The planets Saturn and Mercury will lie nearby, but lower on the horizon and they might be challenging to spot in the bright morning twilight.
Look for Venus in the sunrise direction on any clear morning now. It’s visible not just in a dark sky, but in bright morning twilight as well.
Need an exact measure? At greatest brilliancy on April 27, 2025, Venus will shine at magnitude -4.7. That’s super bright! It’ll reach this brightness at 17 UTC on April 27.
After late April 2025, Venus won’t appear this bright to us again in the morning sky until November 2026.
When does it happen?
Venus was at greatest brilliancy in the evening sky on February 14. Then, Venus sank toward the sunset as it raced toward its sweep between the Earth and sun – its inferior conjunction – on March 23, 2025.
Afterwards, this bright planet quickly emerged into the morning sky. Earth and Venus are constantly moving in their orbits around the sun. Venus moves faster, and its orbit is smaller than Earth’s orbit. So Venus “laps” Earth every so often. Venus comes to inferior conjunction about every 19.5 months, or roughly 584 days. When it does this, it always moved from our evening to our morning sky. And there are always two times of greatest brilliancy surrounding inferior conjunction, one in the evening, followed by one in the morning.
Venus’ greatest brilliancy always happens about a month before – and after – Venus reaches inferior conjunction. Its next inferior conjunction – when it’ll move to the morning sky – is October 2026.
Earth and Venus orbit the sun counterclockwise as seen from the north side of the solar system. Venus reaches its greatest eastern elongation in the evening sky about 72 days before inferior conjunction and its greatest western elongation in the morning sky about 72 days after inferior conjunction. Greatest illuminated extent for Venus comes midway between a greatest elongation and an inferior conjunction. Adapted from an image by Wmheric/ Wikimedia Commons (CC BY-SA 3.0).
Why does it happen?
Greatest brilliancy for Venus is a combination of two factors: illumination and disk size. Venus was at superior conjunction – on the opposite side of the sun from Earth – on June 4, 2024. At superior conjunction, when Venus is on the far side of the sun from us, it’s at full phase and its disk size is always small. It emerged in the evening twilight in late July 2024. Then its disk size increased as its phase decreased and it reached its greatest brilliancy in the evening sky on Valentine’s Day, February 14, 2025.
Now at greatest brilliancy in the morning sky, we’re not seeing a fully illuminated Venus. Instead, as seen through telescopes – as Venus races away from Earth – its phase has been increasing, like a waxing crescent moon. Meanwhile, again as seen through telescopes, the disk size of Venus has been decreasing as the planet races ahead of Earth in orbit around the sun.
View at EarthSky Community Photos. | P Govardhana Siddartha of India submitted this composite of Venus taken over 4 month. Venus was recorded from December 2024 to March 2025 as it raced toward inferior conjunction in March. You can see how the size of Venus increased and the phase decreased during that time. Thank you, P Govardhana!
It’s a combination of phase and size
Greatest illuminated extent. It’s only when we see Venus as a crescent that this world comes close enough to us to exhibit its greatest illuminated extent, at which time its daytime side covers the greatest area of sky. And that means that Venus is brighter around now than at any other time during its approximate 7-month reign in the morning sky.
Disk size. Remember, again as seen through a telescope, the disk of Venus decreases after inferior conjunction. In July, 2024, Venus was around a 10-arcsecond gibbous disk through telescopes. At its greatest brilliancy in the February evening sky, Venus was around a 40-arcsecond crescent disk. Now at its greatest brilliancy in the morning sky on April 27, its disk size will be 40.7-arcseconds.
So greatest brilliancy for Venus is a combination of maximum phase and disk size. The two combine to give us a bright planet Venus.
Then, as it races away from us, the phase continues to increase … but the disk size decreases. So Venus will start to appear a smidgeon fainter to us following April 27, and fainter still (but still very bright!) until it slips away in in the sun’s glare in November 2025.
The phases of Venus – and its locations at inferior and superior conjunction – as viewed from Earth. Adapted from an image by NASA/ Chmee2/ Wikimedia Commons (CC BY-SA 3.0).
Venus charts for 2025, from Guy Ottewell
Venus’s greatest morning elongation in 2025 from the Northern Hemisphere as viewed through a powerful telescope. The planet images are at the 1st, 11th, and 21st of each month. Dots show the actual positions of Venus every day. Chart via Guy Ottewell’s 2025 Astronomical Calendar. Used with permission.Venus’s greatest morning elongation in 2025 from the Southern Hemisphere as viewed through a powerful telescope. The planet images are at the 1st, 11th, and 21st of each month. Dots show the actual positions of Venus every day. Chart via Guy Ottewell’s 2025 Astronomical Calendar. Used with permission.
Venus photos from our community
View at EarthSky Community Photos. | Eliot Herman of Arizona, submitted thisi photo on February 17, 2025, and wrote: “Venus at -4.87 magnitude and 43.1 arcseconds diameter. This is about the maximum brightness of Venus for 2025 evening planet.” Thank you, Eliot!View at EarthSky Community Photos. | EarthSky’s Deborah Byrd caught Venus with an iPhone, over the desert west of Santa Fe, New Mexico, on September 14, 2023. It was super bright! It’s easy to see, even from cities.View at EarthSky Community Photos. | Vedant Pandey wrote: “I am Vedant Pandey, a 17-year-old amateur astrophotographer from Varanasi, Uttar Pradesh, India. I photographed Venus since it appeared in the evening sky in February 2023. And here are the phases of Venus, from waxing gibbous in February to its crescent phase in August, as seen by my telescope.” Wow! Thank you, Vedant!
More Venus images
View at EarthSky Community Photos. | Roberto Ortu of Cabras, Sardinia, Italy, captured these images of Venus and wrote: “This is a mosaic with the best photos of the planet that I got from May 23, 2023, until August 8, 2023. The images show its phases, very similar to those of the moon, and the increase in its apparent diameter caused by the approach to the Earth.” Thank you, Roberto!View larger. | This composite image shows how Venus changes in size and phases as it gets closer to Earth. Image via Tom and Jane Wildoner/ Dark Side Observatory. Used with permission.This image of Venus was captured during daylight when Venus was 6% illuminated. Image via Tom and Jane Wildoner/ Dark Side Observatory. Used with permission.
Bottom line: Venus will be brightest in the morning sky around April 27, 2025. After that, Venus will next be at its brightest again – this time in the evening sky – in September 2026.
View larger. | This artist’s illustration depicts Titan’s organic-rich surface, with a lake near the north pole. Hydrocarbons coat the icy surface, hang in the atmosphere as smog and are the liquids in the seas and lakes. So, could there be life on Titan? A new study suggests it would most likely be in the subsurface ocean below and be limited to only a few pounds of microbes for the entire moon. Image via NASA/ JPL-Caltech/ NASA Photojournal.
Titan, Saturn’s largest moon, is rich in organic molecules. They are on the surface, in the lakes and seas and in the atmosphere. Does that mean Titan could have life?
Titan’s global subsurface ocean would be the best place for life to survive. But a new study says that only a small amount of organics, as a food source, could make their way into the ocean from the surface.
Microbial life in Titan’s ocean would likely be limited to only a few pounds’ worth, in the entire ocean.
Is there life on Titan?
Could Saturn’s moon Titan support life? Titan has seas, lakes and rivers of methane and ethane. Its atmosphere is mostly nitrogen, like Earth’s. It even has a subsurface ocean. But it is also extremely cold on the surface, far colder than any place on Earth. On April 7, 2025, an international team of researchers said that while microscopic life could exist on Titan, most likely in the subsurface ocean, it would likely be a tiny amount. Only a few pounds’ worth for the whole moon, in fact.
The researchers published their peer-reviewed findings in The Planetary Science Journal on April 7, 2025.
NASA’s Cassini spacecraft captured this composite infrared image of Saturn’s moon Titan in 2015. Image via NASA/ JPL/ University of Arizona/ University of Idaho.
Abundant organics on Titan
One thing that makes Titan unique among solar system moons is the amount of organic material on its surface. The moon’s atmosphere is filled with a hydrocarbon smog, and hydrocarbons coat the surface as dunes. Hydrocarbons are organic compounds consisting entirely of hydrogen and carbon. Lead author Antonin Affholder at the University of Arizona’s Department of Ecology and Evolutionary Biology said:
In our study, we focus on what makes Titan unique when compared to other icy moons: its plentiful organic content.
Organic molecules are, of course, needed for life. But their presence doesn’t guarantee that life itself exists, however.
Life on Titan?
The organics on Titan could also theoretically serve as food sources for microbes. But while there are lakes and seas on Titan, they are composed of liquid methane and ethane, not water. The extreme cold, where those gases can be liquid, would make life on the surface difficult, if not unlikely. The researchers said the best place to look for life would be in Titan’s global subsurface water ocean. Scientists estimate it to be up to 300 miles (480 km) deep.
Indeed, the vast ocean would seem the ideal place for life to thrive, if it ever got started on Titan. But most of the organic material, as far as we know, is on the surface. And there is limited transfer of material between the surface and underground ocean. As a result, that could make life less likely, or at least sparser. Affholder said:
There has been this sense that because Titan has such abundant organics, there is no shortage of food sources that could sustain life. We point out that not all of these organic molecules may constitute food sources, the ocean is really big, and there’s limited exchange between the ocean and the surface, where all those organics are, so we argue for a more nuanced approach.
Antonin Affholder at The University of Arizona is the lead author of the new study about possible microbial life on Titan. Image via NOMIS Foundation.
Fermentation-based life
So, since the ocean is closed off from the surface, what kind of microbial life could survive in it? The researchers say that it could be based on a very simple chemical process found on Earth: fermentation. Those kinds of microbes would only need organic molecules for food and not require sunlight or even oxygen. It’s the same fermentation process used to bake sourdough bread and brew beer. In fact, it’s one of the earliest known biological processes to have occurred on Earth. As Affholder noted:
Fermentation probably evolved early in the history of Earth’s life, and does not require us to open any door into unknown or speculative mechanisms that may or may not have happened on Titan.
On Titan, fermentation could involve the organic molecule called glycine. It’s the simplest type of amino acid. Affholder said:
We know that glycine was relatively abundant in any sort of primordial matter in the solar system. When you look at asteroids, comets, the clouds of particles and gas from which stars and planets like our solar system form, we find glycine or its precursors in pretty much all those places.
View larger. | Artist’s concept of NASA’s Dragonfly drone, slated for launch to Saturn’s moon Titan in July 2028. It’s due to arrive at Titan in 2034. Among other goals, it’ll examine Selk Crater, which scientists believe used to hold a liquid water lake on Titan. In addition, Dragonfly will also search for organic molecules – the building blocks of life – that might have formed in that ancient lake. Image via NASA/ Johns Hopkins APL/ Steve Gribben/ Wikimedia Commons (Public domain).
Only a few pounds of life?
So if fermentation-based life could exist in Titan’s ocean, then how much life could the ocean sustain? Ultimately, it depends on how much of the organic material, including amino acids, is suitable as a food source. And that, the study concluded, might only be a small amount. But there should be at least some, however. In previous studies, the same scientists had shown that meteorites hitting Titan’s icy surface would create temporary melt pools of liquid water. That water could sink downward through the ice and bring organic compounds to the ocean below.
However, the new study found it would be a limited amount of organics. It would be enough to sustain a few pounds’ worth of microbes at most in the entire ocean. Affholder said:
Our new study shows that this supply may only be sufficient to sustain a very small population of microbes weighing a total of only a few kilograms [or pounds] at most, equivalent to the mass of a small dog. Such a tiny biosphere would average less than one cell per liter of water over Titan’s entire vast ocean.
On the other hand, at least each microbe would have plenty of room to swim around!
Bottom line: Could there be microbial life on Titan? New research suggests that despite being rich in organics, Titan might only be able to support a few pounds of microbes.
View larger. | This artist’s illustration depicts Titan’s organic-rich surface, with a lake near the north pole. Hydrocarbons coat the icy surface, hang in the atmosphere as smog and are the liquids in the seas and lakes. So, could there be life on Titan? A new study suggests it would most likely be in the subsurface ocean below and be limited to only a few pounds of microbes for the entire moon. Image via NASA/ JPL-Caltech/ NASA Photojournal.
Titan, Saturn’s largest moon, is rich in organic molecules. They are on the surface, in the lakes and seas and in the atmosphere. Does that mean Titan could have life?
Titan’s global subsurface ocean would be the best place for life to survive. But a new study says that only a small amount of organics, as a food source, could make their way into the ocean from the surface.
Microbial life in Titan’s ocean would likely be limited to only a few pounds’ worth, in the entire ocean.
Is there life on Titan?
Could Saturn’s moon Titan support life? Titan has seas, lakes and rivers of methane and ethane. Its atmosphere is mostly nitrogen, like Earth’s. It even has a subsurface ocean. But it is also extremely cold on the surface, far colder than any place on Earth. On April 7, 2025, an international team of researchers said that while microscopic life could exist on Titan, most likely in the subsurface ocean, it would likely be a tiny amount. Only a few pounds’ worth for the whole moon, in fact.
The researchers published their peer-reviewed findings in The Planetary Science Journal on April 7, 2025.
NASA’s Cassini spacecraft captured this composite infrared image of Saturn’s moon Titan in 2015. Image via NASA/ JPL/ University of Arizona/ University of Idaho.
Abundant organics on Titan
One thing that makes Titan unique among solar system moons is the amount of organic material on its surface. The moon’s atmosphere is filled with a hydrocarbon smog, and hydrocarbons coat the surface as dunes. Hydrocarbons are organic compounds consisting entirely of hydrogen and carbon. Lead author Antonin Affholder at the University of Arizona’s Department of Ecology and Evolutionary Biology said:
In our study, we focus on what makes Titan unique when compared to other icy moons: its plentiful organic content.
Organic molecules are, of course, needed for life. But their presence doesn’t guarantee that life itself exists, however.
Life on Titan?
The organics on Titan could also theoretically serve as food sources for microbes. But while there are lakes and seas on Titan, they are composed of liquid methane and ethane, not water. The extreme cold, where those gases can be liquid, would make life on the surface difficult, if not unlikely. The researchers said the best place to look for life would be in Titan’s global subsurface water ocean. Scientists estimate it to be up to 300 miles (480 km) deep.
Indeed, the vast ocean would seem the ideal place for life to thrive, if it ever got started on Titan. But most of the organic material, as far as we know, is on the surface. And there is limited transfer of material between the surface and underground ocean. As a result, that could make life less likely, or at least sparser. Affholder said:
There has been this sense that because Titan has such abundant organics, there is no shortage of food sources that could sustain life. We point out that not all of these organic molecules may constitute food sources, the ocean is really big, and there’s limited exchange between the ocean and the surface, where all those organics are, so we argue for a more nuanced approach.
Antonin Affholder at The University of Arizona is the lead author of the new study about possible microbial life on Titan. Image via NOMIS Foundation.
Fermentation-based life
So, since the ocean is closed off from the surface, what kind of microbial life could survive in it? The researchers say that it could be based on a very simple chemical process found on Earth: fermentation. Those kinds of microbes would only need organic molecules for food and not require sunlight or even oxygen. It’s the same fermentation process used to bake sourdough bread and brew beer. In fact, it’s one of the earliest known biological processes to have occurred on Earth. As Affholder noted:
Fermentation probably evolved early in the history of Earth’s life, and does not require us to open any door into unknown or speculative mechanisms that may or may not have happened on Titan.
On Titan, fermentation could involve the organic molecule called glycine. It’s the simplest type of amino acid. Affholder said:
We know that glycine was relatively abundant in any sort of primordial matter in the solar system. When you look at asteroids, comets, the clouds of particles and gas from which stars and planets like our solar system form, we find glycine or its precursors in pretty much all those places.
View larger. | Artist’s concept of NASA’s Dragonfly drone, slated for launch to Saturn’s moon Titan in July 2028. It’s due to arrive at Titan in 2034. Among other goals, it’ll examine Selk Crater, which scientists believe used to hold a liquid water lake on Titan. In addition, Dragonfly will also search for organic molecules – the building blocks of life – that might have formed in that ancient lake. Image via NASA/ Johns Hopkins APL/ Steve Gribben/ Wikimedia Commons (Public domain).
Only a few pounds of life?
So if fermentation-based life could exist in Titan’s ocean, then how much life could the ocean sustain? Ultimately, it depends on how much of the organic material, including amino acids, is suitable as a food source. And that, the study concluded, might only be a small amount. But there should be at least some, however. In previous studies, the same scientists had shown that meteorites hitting Titan’s icy surface would create temporary melt pools of liquid water. That water could sink downward through the ice and bring organic compounds to the ocean below.
However, the new study found it would be a limited amount of organics. It would be enough to sustain a few pounds’ worth of microbes at most in the entire ocean. Affholder said:
Our new study shows that this supply may only be sufficient to sustain a very small population of microbes weighing a total of only a few kilograms [or pounds] at most, equivalent to the mass of a small dog. Such a tiny biosphere would average less than one cell per liter of water over Titan’s entire vast ocean.
On the other hand, at least each microbe would have plenty of room to swim around!
Bottom line: Could there be microbial life on Titan? New research suggests that despite being rich in organics, Titan might only be able to support a few pounds of microbes.
View at EarthSky Community Photos. | Brian Mack captured this image on January 16, 2025, from Big Sur, California. Brian wrote: “Saturn and Venus low over the coast of Central California. The moon is just rising behind me, providing enough lighting for the landscape and ocean to expose in the photograph as well.” Thank you, Brian! Read on to find out why Venus is so bright.
Have you noticed a bright object in the eastern sky before sunrise? That’s Venus. Here’s why it’s so bright.
Jupiter is a bright planet, and Mars is sometimes bright, too. But neither Jupiter nor Mars at their brightest can outshine Venus. The first few months of 2025 found all three planets in our evening sky. Since then, Venus emerged in the morning sky in late March and is now on its way to its greatest brilliancy in the morning sky on April 27.
So why is Venus so bright?
Our neighboring world – orbiting one step inward from Earth around the sun – is the third-brightest natural object in the sky, after the sun and the moon. It’s currently a brilliant light ascending in the morning sky, shining at magnitude -4.6. Greatest brilliancy for Venus for this 2025 morning apparition will happen on April 27.
Look at the photo above. Venus now appears as a crescent – through telescopes – as seen from Earth. How can a crescent Venus appear brighter to us than the fuller Venus we see at other times?
Albedo = reflectivity
As the planet next inward from Earth in orbit around the sun, Venus is relatively nearby. But its nearness isn’t the only reason Venus is bright. Consider that Mars orbits one step outward from Earth. And Mars waxes and wanes in brightness in our sky over about a two-year cycle. It’s only exceptionally bright around the time Earth passes between Mars and the sun, at the same time Mars is closest to the sun. The last time that happened was in 2018. And the next time will be in 2035.
With Venus, something else is going on. Astronomers use the term albedo to describe how bright a planet is in absolute terms. When sunlight strikes a planet, the planet’s surface absorbs some of the light and reflects the rest.
Albedo is a comparison between how much light strikes an object and how much the object reflects. And, as you might have guessed, Venus has the highest albedo of any major planet in our solar system.
Reflectivity makes Venus bright
The albedo of Venus is close to 0.7, meaning it reflects about 70% of the sunlight striking it. When the moon is close to full in Earth’s sky, it can look a lot brighter than Venus. But the moon – whose surface is dark volcanic rock – reflects only about 10% of the light that hits it. The moon appears bright to us because it’s close to Earth. It’s only about a light-second away, in contrast to the several light-minutes distance of Venus.
Venus is bright (it has a high albedo) because it’s blanketed by highly reflective clouds. The clouds in the atmosphere of Venus contain droplets of sulfuric acid, as well as acidic crystals suspended in a mixture of gases. Light bounces easily off the smooth surfaces of these spheres and crystals. Sunlight bouncing from these clouds is a big part of why Venus is so bright.
By the way, Venus is the brightest major planet. But it isn’t the most reflective body in our solar system. That honor goes to Enceladus, a moon of Saturn. The little moon’s icy surface reflects some 90% of the sunlight striking it.
Venus is brightest when two factors combine – the phase of its crescent, plus largest overall size of Venus’ disk – so that the greatest amount of surface area of Venus shows in our sky. Astronomers call this greatest illuminated extent.
Why does it happen? Because Venus orbits the sun inside Earth’s orbit, it sometimes goes between us and the sun. At such times, its lighted hemisphere, or day side, is facing away from us. Then it’s difficult to see Venus at all (though experienced astrophotographers sometimes catch it).
Also, around the time it passes between us and the sun – known as inferior conjunction – we see Venus exhibit phases … like a tiny moon. Venus reached inferior conjunction on March 22-23, 2025. Now Venus is racing ahead of Earth in our orbits – it “lapped” us in the race of the planets – observers on Earth can watch as the phase of Venus waxes. As Venus moves away from its inferior conjunction, it’ll decrease in size as its phase increases.
And now that Venus is racing ahead of us in orbit, we see Venus wax in phase. As the crescent Venus waxes in Earth’s sky, the overall size of the disk of Venus gets smaller in our sky, as Venus speeds ahead of us.
View at EarthSky Community Photos. | Tameem Altameemi captured this image from Dubai and wrote: “This image beautifully captures a fascinating astronomical phenomenon: the similarity between the moon’s and Venus’s phases. Venus, like the moon, goes through phases as seen from Earth. This happens because Venus orbits inside Earth’s orbit, making it an inferior planet. The phase of Venus changes as its position relative to the sun and Earth shifts, like how the moon’s phases change.” Thank you, Tameem!
Venus at greatest brilliancy soon
Venus passed between us and the sun at 1 UTC on March 23, 2025. Since then, it’s been rushing ahead of us in orbit. Its phase will be increasing. But its disk size will be decreasing. Greatest brilliancy happens when we see the greatest illuminated surface area of Venus: a combination of phase size and disk size. Astronomers call this a “greatest illuminated extent” of Venus.
It’s happening now in the east before sunrise! Don’t miss Venus blazing before twilight begins April 27, 2025. Or look for it that morning in the bright twilight. It’ll reach greatest brilliancy in the morning sky on April 27, 2025. Check Stellarium.org for local times.
The phases of Venus – and its locations at inferior and superior conjunction – as viewed from Earth. Adapted from an image by NASA/ Chmee2/ Wikimedia Commons(CC BY-SA 3.0).
A thin waning crescent moon will hang low above the eastern horizon on April 23 and 24, 2025. Brilliant Venus will shine nearby with the much dimmer Saturn closer to the horizon. Venus and Saturn will be closest to each other on the morning of April 29 when they are 4 degrees apart. Look for them about 40 minutes before sunrise. Chart via EarthSky.About 30 minutes before sunrise on April 25, 2025, the thin waning crescent moon will form a triangle with brilliant Venus and the much dimmer Saturn. Do you see a delicate glow on the unlit portion of the moon? That’s light reflected off Earth called earthshine. Chart via EarthSky.Venus will be bright all month and will lie above the much dimmer Saturn and Mercury. At 17 UTC on April 27, 2025, it will reach its point of greatest brilliancy in the morning sky. After late April 2025, Venus won’t appear this bright to us again in the morning sky until November 2026. But it remains a bright morning object through the fall of 2025. Chart via EarthSky.
More photos from our community
View at EarthSky Community Photo. | Gwen Forrester of DeKalb County, Tennessee, captured these images on February 3, 2025. Gwen wrote: “Venus has been shining at its brightest recently, accompanied by the waxing crescent moon, as its own crescent phase wanes. Tonight, they were at roughly equal illumination as viewed from Earth.” Thank you, Gwen!View at EarthSky Community Photos. | P Govardhana Siddartha of India submitted this composite of Venus taken over 4 months. Venus was recorded from December 2024 to March 2025 as it raced toward inferior conjunction in March. You can see how the size of Venus increases and the phase decreases. Thank you, P Govardhana!
Bottom line: Look for dazzling Venus in the east before dawn and in the morning twilight. It’s the 3rd brightest object in the sky, after the sun and moon. But why is Venus so bright?
View at EarthSky Community Photos. | Brian Mack captured this image on January 16, 2025, from Big Sur, California. Brian wrote: “Saturn and Venus low over the coast of Central California. The moon is just rising behind me, providing enough lighting for the landscape and ocean to expose in the photograph as well.” Thank you, Brian! Read on to find out why Venus is so bright.
Have you noticed a bright object in the eastern sky before sunrise? That’s Venus. Here’s why it’s so bright.
Jupiter is a bright planet, and Mars is sometimes bright, too. But neither Jupiter nor Mars at their brightest can outshine Venus. The first few months of 2025 found all three planets in our evening sky. Since then, Venus emerged in the morning sky in late March and is now on its way to its greatest brilliancy in the morning sky on April 27.
So why is Venus so bright?
Our neighboring world – orbiting one step inward from Earth around the sun – is the third-brightest natural object in the sky, after the sun and the moon. It’s currently a brilliant light ascending in the morning sky, shining at magnitude -4.6. Greatest brilliancy for Venus for this 2025 morning apparition will happen on April 27.
Look at the photo above. Venus now appears as a crescent – through telescopes – as seen from Earth. How can a crescent Venus appear brighter to us than the fuller Venus we see at other times?
Albedo = reflectivity
As the planet next inward from Earth in orbit around the sun, Venus is relatively nearby. But its nearness isn’t the only reason Venus is bright. Consider that Mars orbits one step outward from Earth. And Mars waxes and wanes in brightness in our sky over about a two-year cycle. It’s only exceptionally bright around the time Earth passes between Mars and the sun, at the same time Mars is closest to the sun. The last time that happened was in 2018. And the next time will be in 2035.
With Venus, something else is going on. Astronomers use the term albedo to describe how bright a planet is in absolute terms. When sunlight strikes a planet, the planet’s surface absorbs some of the light and reflects the rest.
Albedo is a comparison between how much light strikes an object and how much the object reflects. And, as you might have guessed, Venus has the highest albedo of any major planet in our solar system.
Reflectivity makes Venus bright
The albedo of Venus is close to 0.7, meaning it reflects about 70% of the sunlight striking it. When the moon is close to full in Earth’s sky, it can look a lot brighter than Venus. But the moon – whose surface is dark volcanic rock – reflects only about 10% of the light that hits it. The moon appears bright to us because it’s close to Earth. It’s only about a light-second away, in contrast to the several light-minutes distance of Venus.
Venus is bright (it has a high albedo) because it’s blanketed by highly reflective clouds. The clouds in the atmosphere of Venus contain droplets of sulfuric acid, as well as acidic crystals suspended in a mixture of gases. Light bounces easily off the smooth surfaces of these spheres and crystals. Sunlight bouncing from these clouds is a big part of why Venus is so bright.
By the way, Venus is the brightest major planet. But it isn’t the most reflective body in our solar system. That honor goes to Enceladus, a moon of Saturn. The little moon’s icy surface reflects some 90% of the sunlight striking it.
Venus is brightest when two factors combine – the phase of its crescent, plus largest overall size of Venus’ disk – so that the greatest amount of surface area of Venus shows in our sky. Astronomers call this greatest illuminated extent.
Why does it happen? Because Venus orbits the sun inside Earth’s orbit, it sometimes goes between us and the sun. At such times, its lighted hemisphere, or day side, is facing away from us. Then it’s difficult to see Venus at all (though experienced astrophotographers sometimes catch it).
Also, around the time it passes between us and the sun – known as inferior conjunction – we see Venus exhibit phases … like a tiny moon. Venus reached inferior conjunction on March 22-23, 2025. Now Venus is racing ahead of Earth in our orbits – it “lapped” us in the race of the planets – observers on Earth can watch as the phase of Venus waxes. As Venus moves away from its inferior conjunction, it’ll decrease in size as its phase increases.
And now that Venus is racing ahead of us in orbit, we see Venus wax in phase. As the crescent Venus waxes in Earth’s sky, the overall size of the disk of Venus gets smaller in our sky, as Venus speeds ahead of us.
View at EarthSky Community Photos. | Tameem Altameemi captured this image from Dubai and wrote: “This image beautifully captures a fascinating astronomical phenomenon: the similarity between the moon’s and Venus’s phases. Venus, like the moon, goes through phases as seen from Earth. This happens because Venus orbits inside Earth’s orbit, making it an inferior planet. The phase of Venus changes as its position relative to the sun and Earth shifts, like how the moon’s phases change.” Thank you, Tameem!
Venus at greatest brilliancy soon
Venus passed between us and the sun at 1 UTC on March 23, 2025. Since then, it’s been rushing ahead of us in orbit. Its phase will be increasing. But its disk size will be decreasing. Greatest brilliancy happens when we see the greatest illuminated surface area of Venus: a combination of phase size and disk size. Astronomers call this a “greatest illuminated extent” of Venus.
It’s happening now in the east before sunrise! Don’t miss Venus blazing before twilight begins April 27, 2025. Or look for it that morning in the bright twilight. It’ll reach greatest brilliancy in the morning sky on April 27, 2025. Check Stellarium.org for local times.
The phases of Venus – and its locations at inferior and superior conjunction – as viewed from Earth. Adapted from an image by NASA/ Chmee2/ Wikimedia Commons(CC BY-SA 3.0).
A thin waning crescent moon will hang low above the eastern horizon on April 23 and 24, 2025. Brilliant Venus will shine nearby with the much dimmer Saturn closer to the horizon. Venus and Saturn will be closest to each other on the morning of April 29 when they are 4 degrees apart. Look for them about 40 minutes before sunrise. Chart via EarthSky.About 30 minutes before sunrise on April 25, 2025, the thin waning crescent moon will form a triangle with brilliant Venus and the much dimmer Saturn. Do you see a delicate glow on the unlit portion of the moon? That’s light reflected off Earth called earthshine. Chart via EarthSky.Venus will be bright all month and will lie above the much dimmer Saturn and Mercury. At 17 UTC on April 27, 2025, it will reach its point of greatest brilliancy in the morning sky. After late April 2025, Venus won’t appear this bright to us again in the morning sky until November 2026. But it remains a bright morning object through the fall of 2025. Chart via EarthSky.
More photos from our community
View at EarthSky Community Photo. | Gwen Forrester of DeKalb County, Tennessee, captured these images on February 3, 2025. Gwen wrote: “Venus has been shining at its brightest recently, accompanied by the waxing crescent moon, as its own crescent phase wanes. Tonight, they were at roughly equal illumination as viewed from Earth.” Thank you, Gwen!View at EarthSky Community Photos. | P Govardhana Siddartha of India submitted this composite of Venus taken over 4 months. Venus was recorded from December 2024 to March 2025 as it raced toward inferior conjunction in March. You can see how the size of Venus increases and the phase decreases. Thank you, P Govardhana!
Bottom line: Look for dazzling Venus in the east before dawn and in the morning twilight. It’s the 3rd brightest object in the sky, after the sun and moon. But why is Venus so bright?
Watch this video about the unique Mexican burrowing toad.
The Mexican burrowing toad, scientifically known as Rhinophrynus dorsalis, has specialized characteristics that make it unique among amphibians. It looks like a deflated balloon and blends in impressively with its environment. And, as its name suggests, this toad is a skillful digger. While you can find it in Mexico, it also lives in areas from southern Texas to Costa Rica.
Physical appearance of the Mexican burrowing toad
There are three orders of amphibians: Those with tails (like salamanders and newts), those without tails (like frogs and toads) and those without legs (like caecilians). This amphibian is a toad, but one that’s quite different from the rest.
One of the Mexican burrowing toad’s most distinctive characteristics is its specialized snout. Being short, robust and rounded, these snouts can pierce the ground and dig tunnels with great ease. Although its mouth is small, shock-absorbing pads surround it. Furthermore, each cell around the mouth is armed with a strong keratin tip. This likely protects the mouth when the animal pushes forward through the soil.
In addition, its legs are short, strong and great for digging. Its feet have special features for burrowing, including nail-like, keratinized structures at the tips of each toe. The front feet don’t have webbing between the toes, allowing for easier digging, while the heavily webbed back feet are short.
The Mexican burrowing toad also has small, upward-facing eyes, allowing it to monitor its surroundings while remaining partially buried underground. This elusive animal digs with agility and quickly hides to protect itself from predators, such as birds, mammals and snakes.
Its body reaches a length of 2.4 to 3.5 inches (6 to 9 cm), although females are considerably larger. They resemble a small deflated balloon with thick, rough skin. The dorsal part is dark brown or almost black, giving it camouflage in the mud as protection from potential predators.
A clear vertebral line extends from the head to the rear. It also has scattered dots and spots in yellow, orange or red, especially on the sides. The belly can be dark brown, purple-blue or gray.
An adult Mexican burrowing toad. Image via Greg Schechter/ Wikipedia (CC BY 2.0).
What can the Mexican burrowing toad do?
Mexican burrowing toads prefer tropical and subtropical habitats with distinct rainy and dry seasons. During periods of heavy rain, they live in places with dense vegetation: Mainly grasslands, crop fields, ditches, and ponds. In drier seasons, they burrow in the soil.
In fact, this amphibian is known for its ability to burrow and live underground for long periods. For most of its life, it remains buried in self-excavated tunnels. These tunnels provide protection from temperature changes and lack of water during dry seasons. Its subterranean behavior allows it to escape the intense heat of the surface. It’s also a key adaptation for survival in the arid areas of central and northern Mexico and southern Texas. One of the most remarkable things about this toad is its ability to survive in extreme conditions.
The Mexican burrowing toad has developed a tolerance to dehydration. It stores water in its tissues, making it resilient to water shortages, a useful adaptation in arid and semi-arid environments. Its thick skin acts as a barrier to prevent excessive water loss.
This species lives in tunnels for most of its life. It only goes out during rainy periods. Image via Greg Schechter/ Wikipedia (CC BY 2.0).
Rainy seasons and tadpoles
Mexican burrowing toads are nocturnal. That means they are most active at night, when temperatures are cooler and humidity is higher. And during the rainy season, the toads emerge from their tunnels at night to reproduce.
The female lays her eggs in small temporary pools of water, where the young develop into tadpoles. And once the tadpoles have developed, the adults return to their burrows to spend the rest of the year buried.
This is a young Mexican burrowing toad. Image via Jose Colorado Dapa/ iNaturalist (CC BY-SA 4.0).
Fun facts
Different tongue: The toad’s snout is protected by a layer of small, keratinous spines, and its lips are sealed by secretions from glands beneath the lower jaw. These lips feature a double closure along the curved upper jawbone, further reinforced by the jaw’s glands.
In addition, this toad uses a unique method of tongue protrusion, setting it apart from frogs. While most frogs flick their tongues out quickly through their lips, this species stiffens its tongue and extends it by moving the jaw backward. This specialized mechanism helps it capture small insects hiding in burrows.
No neck: This species has no neck and no visible ear holes or tympanum (an external hearing structure).
Balloon shape: When the toad becomes alarmed, it inflates its body and resembles a balloon, with its already short head and limbs almost disappearing.
Endangered species: Although the Mexican burrowing toad is not currently in immediate danger of extinction, its population is threatened by habitat loss due to urban growth and agriculture. Water pollution can also negatively affect tadpoles, as they depend on temporary bodies of water to complete their life cycle.
Mexican burrowing toads are well camouflaged for their environments. Image via Juan Cruzado/ iNaturalist (CC BY-SA 4.0).
Why is it important to the ecosystem?
This order of amphibians – anurans – are an important part of ecosystems. Some research has shown that when these animals disappear from habitats (whether due to pollution or destruction), ecosystems are altered. This happens because anurans feed on insects. When these amphibians disappear, populations of harmful species increase. For example, some insects (mosquitoes, bed bugs, crickets, etc.) can become pests.
Furthermore, the increase in insects such as mosquitoes represents a health problem, since they transmit diseases. By increasing their populations and expanding their distribution areas, these insects carry and spread diseases such as malaria and dengue fever at an alarming rate on a global scale.
In turn, anurans also serve as food for larger organisms, such as birds, small mammals and even humans. To ensure their survival, these toads produce thousands of offspring at a time. A considerable advantage is that they do not require parental care. That is, adults do not protect the tadpoles after they hatch.
Furthermore, the tadpoles also play an important role in maintaining the health of freshwater ecosystems. This is because they control the growth of algae in rivers and lakes. Without these tadpoles, other organisms, such as fish, would be affected.
This little friend plays a key role in maintaining healthy ecosystems. Image via Juan Cruzado/ iNaturalist (CC BY-SA 4.0).
A key role for healthy ecosystems
The Mexican burrowing toad is a clear example of how evolution has endowed living beings with extraordinary adaptations to survive in hostile environments. Its ability to burrow and live underground, its tolerance for dehydration, and its connection to rainfall are just some of the characteristics that make it unique in the animal kingdom.
Protecting its habitat is crucial not just for ensuring its survival, but for maintaining biodiversity where it lives.
Bottom line: The Mexican burrowing toad is an expert digger. It can build long, deep tunnels and live there for long periods of time. It can survive extreme conditions and plays a key role in maintaining healthy ecosystems.
Watch this video about the unique Mexican burrowing toad.
The Mexican burrowing toad, scientifically known as Rhinophrynus dorsalis, has specialized characteristics that make it unique among amphibians. It looks like a deflated balloon and blends in impressively with its environment. And, as its name suggests, this toad is a skillful digger. While you can find it in Mexico, it also lives in areas from southern Texas to Costa Rica.
Physical appearance of the Mexican burrowing toad
There are three orders of amphibians: Those with tails (like salamanders and newts), those without tails (like frogs and toads) and those without legs (like caecilians). This amphibian is a toad, but one that’s quite different from the rest.
One of the Mexican burrowing toad’s most distinctive characteristics is its specialized snout. Being short, robust and rounded, these snouts can pierce the ground and dig tunnels with great ease. Although its mouth is small, shock-absorbing pads surround it. Furthermore, each cell around the mouth is armed with a strong keratin tip. This likely protects the mouth when the animal pushes forward through the soil.
In addition, its legs are short, strong and great for digging. Its feet have special features for burrowing, including nail-like, keratinized structures at the tips of each toe. The front feet don’t have webbing between the toes, allowing for easier digging, while the heavily webbed back feet are short.
The Mexican burrowing toad also has small, upward-facing eyes, allowing it to monitor its surroundings while remaining partially buried underground. This elusive animal digs with agility and quickly hides to protect itself from predators, such as birds, mammals and snakes.
Its body reaches a length of 2.4 to 3.5 inches (6 to 9 cm), although females are considerably larger. They resemble a small deflated balloon with thick, rough skin. The dorsal part is dark brown or almost black, giving it camouflage in the mud as protection from potential predators.
A clear vertebral line extends from the head to the rear. It also has scattered dots and spots in yellow, orange or red, especially on the sides. The belly can be dark brown, purple-blue or gray.
An adult Mexican burrowing toad. Image via Greg Schechter/ Wikipedia (CC BY 2.0).
What can the Mexican burrowing toad do?
Mexican burrowing toads prefer tropical and subtropical habitats with distinct rainy and dry seasons. During periods of heavy rain, they live in places with dense vegetation: Mainly grasslands, crop fields, ditches, and ponds. In drier seasons, they burrow in the soil.
In fact, this amphibian is known for its ability to burrow and live underground for long periods. For most of its life, it remains buried in self-excavated tunnels. These tunnels provide protection from temperature changes and lack of water during dry seasons. Its subterranean behavior allows it to escape the intense heat of the surface. It’s also a key adaptation for survival in the arid areas of central and northern Mexico and southern Texas. One of the most remarkable things about this toad is its ability to survive in extreme conditions.
The Mexican burrowing toad has developed a tolerance to dehydration. It stores water in its tissues, making it resilient to water shortages, a useful adaptation in arid and semi-arid environments. Its thick skin acts as a barrier to prevent excessive water loss.
This species lives in tunnels for most of its life. It only goes out during rainy periods. Image via Greg Schechter/ Wikipedia (CC BY 2.0).
Rainy seasons and tadpoles
Mexican burrowing toads are nocturnal. That means they are most active at night, when temperatures are cooler and humidity is higher. And during the rainy season, the toads emerge from their tunnels at night to reproduce.
The female lays her eggs in small temporary pools of water, where the young develop into tadpoles. And once the tadpoles have developed, the adults return to their burrows to spend the rest of the year buried.
This is a young Mexican burrowing toad. Image via Jose Colorado Dapa/ iNaturalist (CC BY-SA 4.0).
Fun facts
Different tongue: The toad’s snout is protected by a layer of small, keratinous spines, and its lips are sealed by secretions from glands beneath the lower jaw. These lips feature a double closure along the curved upper jawbone, further reinforced by the jaw’s glands.
In addition, this toad uses a unique method of tongue protrusion, setting it apart from frogs. While most frogs flick their tongues out quickly through their lips, this species stiffens its tongue and extends it by moving the jaw backward. This specialized mechanism helps it capture small insects hiding in burrows.
No neck: This species has no neck and no visible ear holes or tympanum (an external hearing structure).
Balloon shape: When the toad becomes alarmed, it inflates its body and resembles a balloon, with its already short head and limbs almost disappearing.
Endangered species: Although the Mexican burrowing toad is not currently in immediate danger of extinction, its population is threatened by habitat loss due to urban growth and agriculture. Water pollution can also negatively affect tadpoles, as they depend on temporary bodies of water to complete their life cycle.
Mexican burrowing toads are well camouflaged for their environments. Image via Juan Cruzado/ iNaturalist (CC BY-SA 4.0).
Why is it important to the ecosystem?
This order of amphibians – anurans – are an important part of ecosystems. Some research has shown that when these animals disappear from habitats (whether due to pollution or destruction), ecosystems are altered. This happens because anurans feed on insects. When these amphibians disappear, populations of harmful species increase. For example, some insects (mosquitoes, bed bugs, crickets, etc.) can become pests.
Furthermore, the increase in insects such as mosquitoes represents a health problem, since they transmit diseases. By increasing their populations and expanding their distribution areas, these insects carry and spread diseases such as malaria and dengue fever at an alarming rate on a global scale.
In turn, anurans also serve as food for larger organisms, such as birds, small mammals and even humans. To ensure their survival, these toads produce thousands of offspring at a time. A considerable advantage is that they do not require parental care. That is, adults do not protect the tadpoles after they hatch.
Furthermore, the tadpoles also play an important role in maintaining the health of freshwater ecosystems. This is because they control the growth of algae in rivers and lakes. Without these tadpoles, other organisms, such as fish, would be affected.
This little friend plays a key role in maintaining healthy ecosystems. Image via Juan Cruzado/ iNaturalist (CC BY-SA 4.0).
A key role for healthy ecosystems
The Mexican burrowing toad is a clear example of how evolution has endowed living beings with extraordinary adaptations to survive in hostile environments. Its ability to burrow and live underground, its tolerance for dehydration, and its connection to rainfall are just some of the characteristics that make it unique in the animal kingdom.
Protecting its habitat is crucial not just for ensuring its survival, but for maintaining biodiversity where it lives.
Bottom line: The Mexican burrowing toad is an expert digger. It can build long, deep tunnels and live there for long periods of time. It can survive extreme conditions and plays a key role in maintaining healthy ecosystems.
View larger. | One of the Aguas Zarcas meteorites that landed in Costa Rica in 2019. A new study of these meteorites shows that mudball meteorites are not always as weak as scientists assumed. Image via Arizona State University/ SETI Institute.
The Aguas Zarcas meteorites fell to earth in Costa Rica in April 2019. They were mudball meteorites, containing clays, organic compounds and water.
Mudball meteorites are generally weaker than stony meteorites and break apart more easily. But the Aguas Zarcas meteorites were stronger than usual. Why?
The original space rock the meteorites came from didn’t have many collisions with other space rocks. It also didn’t have the typical cracks in it. It therefore remained stronger than usual.
Not all mudball meteorites are weak
Mudball meteorites – or carbonaceous chondrites – are unique. They are rich in clays, organic compounds and water-bearing minerals. As you might expect, they are generally weaker than stony meteorites. But they’re not always as weak as first thought. An international team of scientists has completed a new analysis of the Aguas Zarcas mudball meteorites, which fell near Aguas Zarcas, Costa Rica, in April 2019. The team said on March 31, 2025, that these mudballs were stronger than most, and more of the original space rock survived the impact with Earth’s atmosphere than is typically seen.
The research team published their peer-reviewed results in the journal Meteoritics & Planetary Science on March 29, 2025.
The Aguas Zarcas mudball meteorites
The Aguas Zarcas mudball meteorites fell in Aguas Zarcas, Costa Rica, on April 23, 2019. For scientists, it was one of the largest meteorite hauls of its kind. Lead author and astronomer Peter Jenniskens, at the SETI Institute and NASA Ames Research Center, said:
27 kilos (60 lbs) of rocks were recovered, making this the largest fall of its kind since similar meteorites fell near Murchison in Australia in 1969.
Geologist Gerardo Soto at the University of Costa Rica in San José, paraphrasing astronaut Neil Armstrong on the moon, added:
The recovery of Aguas Zarcas, too, was a small step for man, but a giant leap for meteoritics. 76 papers have since been written about this meteorite. The fall of Aguas Zarcas was huge news in the country. No other fireball was as widely reported and then recovered as stones on the ground in Costa Rica in the last 150 years.
Mudball meteorites were stronger than expected
You would think that meteorites containing clays, organics and water would be weaker than meteorites made of only stone. And you would be right. But the Aguas Zarcas meteorites showed that sometimes, even mudballs can be stronger than anticipated. The original space rock plunged into Earth’s atmosphere at an almost vertical angle. It came from a west-northwest direction at 9 miles per second (14.6 km/s). Indeed, the intense heat did ablate, or melt, much of the rock. However, it didn’t fragment as much as expected. Jenniskens explained:
It penetrated deep into Earth’s atmosphere, until the surviving mass shattered at 16 miles (25 km) above the Earth’s surface, where it produced a bright flash that was detected by satellites in orbit.
That shattering produced the meteorites found later on the ground.
View larger. | Steve Jurvetson (left), Meenakshi Wadhwa (center) and Laurence Garvie (right) at the ASU Center for Meteorite Studies on April 6, 2021. Jurvetson is holding a meteorite from the fall at Aguas Zarcas, Costa Rica, in 2019. Image via Steve Jurvetson/ Wikimedia Commons (CC BY 2.0).
An amazing collection of stones
Many of the meteorites remained intact since they landed on grassy surfaces in jungles. They also had unusual shapes and striking colors. Co-author and meteoriticist Laurence Garvie at the Buseck Center for Meteorite Studies at Arizona State University said:
The Aguas Zarcas fall produced an amazing selection of fusion-crusted stones with a wide range of shapes. Some stones have a beautiful blue iridescence to the fusion crust.
The fact that the meteorites survived as much as they did surprised scientists. They were stronger than expected, as Jenniskens noted:
Other meteorites of this type are often described as mudballs, as they contain water-rich minerals. Apparently, that does not mean they are weak.
Peter Jenniskens at the SETI Institute and NASA Ames Research Center is the lead author of the new Aguas Zarcas meteorites study. Image via SETI Institute.
Why were these meteorites so strong?
So how did these mudball meteorites survive the impact as much as they did? The scientists said there were a couple of reasons. The original Aguas Zarcas space rock – the parent body of the smaller meteorites – didn’t have many collisions with other space rocks. The researchers estimated the last one to be about 2 million years ago. It also didn’t have the kinds of cracks in it that weaken many space rocks. So it was a bit stronger than unusual – at least for a mudball – right from the start.
The space rock that hit Earth’s atmosphere – about 24 inches (60 cm) in size – originated from a larger asteroid. The researchers said the asteroid was likely in the main asteroid belt between Mars and Jupiter. Jenniskens said:
We can tell that this object came from a larger asteroid low in the asteroid belt, likely from its outer regions. After getting loose, it took 2 million years to hit the tiny target of Earth, all the time avoiding getting cracked.
Cosmochemist Kees Welten at UC Berkeley in California added:
We know of other Murchison-like meteorites that broke off at approximately the same time, and likely in the same event, but most broke much more recently.
Bottom line: The Aguas Zarcas mudball meteorites, which landed in Costa Rica in 2019, were stronger than expected. A new study shows that not all mudballs are weak.
View larger. | One of the Aguas Zarcas meteorites that landed in Costa Rica in 2019. A new study of these meteorites shows that mudball meteorites are not always as weak as scientists assumed. Image via Arizona State University/ SETI Institute.
The Aguas Zarcas meteorites fell to earth in Costa Rica in April 2019. They were mudball meteorites, containing clays, organic compounds and water.
Mudball meteorites are generally weaker than stony meteorites and break apart more easily. But the Aguas Zarcas meteorites were stronger than usual. Why?
The original space rock the meteorites came from didn’t have many collisions with other space rocks. It also didn’t have the typical cracks in it. It therefore remained stronger than usual.
Not all mudball meteorites are weak
Mudball meteorites – or carbonaceous chondrites – are unique. They are rich in clays, organic compounds and water-bearing minerals. As you might expect, they are generally weaker than stony meteorites. But they’re not always as weak as first thought. An international team of scientists has completed a new analysis of the Aguas Zarcas mudball meteorites, which fell near Aguas Zarcas, Costa Rica, in April 2019. The team said on March 31, 2025, that these mudballs were stronger than most, and more of the original space rock survived the impact with Earth’s atmosphere than is typically seen.
The research team published their peer-reviewed results in the journal Meteoritics & Planetary Science on March 29, 2025.
The Aguas Zarcas mudball meteorites
The Aguas Zarcas mudball meteorites fell in Aguas Zarcas, Costa Rica, on April 23, 2019. For scientists, it was one of the largest meteorite hauls of its kind. Lead author and astronomer Peter Jenniskens, at the SETI Institute and NASA Ames Research Center, said:
27 kilos (60 lbs) of rocks were recovered, making this the largest fall of its kind since similar meteorites fell near Murchison in Australia in 1969.
Geologist Gerardo Soto at the University of Costa Rica in San José, paraphrasing astronaut Neil Armstrong on the moon, added:
The recovery of Aguas Zarcas, too, was a small step for man, but a giant leap for meteoritics. 76 papers have since been written about this meteorite. The fall of Aguas Zarcas was huge news in the country. No other fireball was as widely reported and then recovered as stones on the ground in Costa Rica in the last 150 years.
Mudball meteorites were stronger than expected
You would think that meteorites containing clays, organics and water would be weaker than meteorites made of only stone. And you would be right. But the Aguas Zarcas meteorites showed that sometimes, even mudballs can be stronger than anticipated. The original space rock plunged into Earth’s atmosphere at an almost vertical angle. It came from a west-northwest direction at 9 miles per second (14.6 km/s). Indeed, the intense heat did ablate, or melt, much of the rock. However, it didn’t fragment as much as expected. Jenniskens explained:
It penetrated deep into Earth’s atmosphere, until the surviving mass shattered at 16 miles (25 km) above the Earth’s surface, where it produced a bright flash that was detected by satellites in orbit.
That shattering produced the meteorites found later on the ground.
View larger. | Steve Jurvetson (left), Meenakshi Wadhwa (center) and Laurence Garvie (right) at the ASU Center for Meteorite Studies on April 6, 2021. Jurvetson is holding a meteorite from the fall at Aguas Zarcas, Costa Rica, in 2019. Image via Steve Jurvetson/ Wikimedia Commons (CC BY 2.0).
An amazing collection of stones
Many of the meteorites remained intact since they landed on grassy surfaces in jungles. They also had unusual shapes and striking colors. Co-author and meteoriticist Laurence Garvie at the Buseck Center for Meteorite Studies at Arizona State University said:
The Aguas Zarcas fall produced an amazing selection of fusion-crusted stones with a wide range of shapes. Some stones have a beautiful blue iridescence to the fusion crust.
The fact that the meteorites survived as much as they did surprised scientists. They were stronger than expected, as Jenniskens noted:
Other meteorites of this type are often described as mudballs, as they contain water-rich minerals. Apparently, that does not mean they are weak.
Peter Jenniskens at the SETI Institute and NASA Ames Research Center is the lead author of the new Aguas Zarcas meteorites study. Image via SETI Institute.
Why were these meteorites so strong?
So how did these mudball meteorites survive the impact as much as they did? The scientists said there were a couple of reasons. The original Aguas Zarcas space rock – the parent body of the smaller meteorites – didn’t have many collisions with other space rocks. The researchers estimated the last one to be about 2 million years ago. It also didn’t have the kinds of cracks in it that weaken many space rocks. So it was a bit stronger than unusual – at least for a mudball – right from the start.
The space rock that hit Earth’s atmosphere – about 24 inches (60 cm) in size – originated from a larger asteroid. The researchers said the asteroid was likely in the main asteroid belt between Mars and Jupiter. Jenniskens said:
We can tell that this object came from a larger asteroid low in the asteroid belt, likely from its outer regions. After getting loose, it took 2 million years to hit the tiny target of Earth, all the time avoiding getting cracked.
Cosmochemist Kees Welten at UC Berkeley in California added:
We know of other Murchison-like meteorites that broke off at approximately the same time, and likely in the same event, but most broke much more recently.
Bottom line: The Aguas Zarcas mudball meteorites, which landed in Costa Rica in 2019, were stronger than expected. A new study shows that not all mudballs are weak.
Daytime moon seen on December 18, 2010. A daytime moon looks ghostly against a blue sky. You can see one after sunrise this week. Look west in the morning hours! Image by Brian Pate. Used with permission.
This month’s full moon came overnight on April 12-13, 2025. So this week’s moon is in a waning gibbous phase. Full moons rise at sunset. But waning gibbous moons rise later – and later – on each successive night.
And that means the moon sets later and later now, too. In the days following every full moon, you’ll find the moon setting in the west after sunrise. That makes the mornings following a full moon a good time to catch a daytime moon. Watch for it during the coming week, after sunrise, over your western horizon. It’ll appear pale against the blue sky. Thanks to what’s called the moon illusion, you might notice the daytime moon looking huge when close to the horizon.
The moon is up in the daytime half of the time. But, because it’s pale against the blue sky, it’s not as noticeable during the day as at night. Still, there are certain windows each month during which the daytime moon is most noticeable.
The coming week presents one of those windows. It’s a good time to watch for a daytime moon in the morning sky.
Then, the next last quarter moon will fall at 1:35 UTC on April 21, 2025. That’s 8:35 p.m. CDT on April 20. It’ll rise after midnight your local time and set around noon. Look for it high in the sky before dawn.
Daytime moon photos from the EarthSky community
View at EarthSky Community Photos. | Peter Lowenstein caught the daytime moon in its waning gibbous phase from Mutare, Zimbabwe. He said: “Three-quarters of an hour after sunrise, I photographed the daytime moon descending toward the top of a flowering African tulip (Spathodia campanulata) tree.” Thank you, Peter!View at EarthSky Community Photos. | Ragini Chaturvedi captured this image on November 14, 2022, in New Jersey. Ragini wrote: “Daytime moon basking in the morning sun, amidst the cold and windy start to the day.” Thank you, Ragini!A daytime moon on January 28, 2013 as seen by EarthSky Facebook friend Denise Johnson in Ridgecrest, California, in the Mojave Desert. Notice that this moon in this photo is closer to the (western) horizon at sunrise than the moon one day later (photo below). Full moon was January 27. Afterwards, the moon is waning again and inching closer to the sun on the sky’s dome.Waning gibbous moon in the west around the time of sunrise, as captured by EarthSky Facebook friend Royce Malacaman in the Philippiines. Thank you, Royce. View larger.Daytime moon – May 27, 2012 – Darren Danks in Netherton UK. See more moon photos at EarthSky’s Facebook page.Daytime moon of May 27, 2012, seen from Ireland. Photo by Damian O’Sullivan. Thank you, Damian! View larger.
Bottom line: You can easily spot the moon in the morning sky – after sunrise – for several days after full moon. Look west after the sun comes up! And a week after the full moon, look high in the sky after dawn.
Daytime moon seen on December 18, 2010. A daytime moon looks ghostly against a blue sky. You can see one after sunrise this week. Look west in the morning hours! Image by Brian Pate. Used with permission.
This month’s full moon came overnight on April 12-13, 2025. So this week’s moon is in a waning gibbous phase. Full moons rise at sunset. But waning gibbous moons rise later – and later – on each successive night.
And that means the moon sets later and later now, too. In the days following every full moon, you’ll find the moon setting in the west after sunrise. That makes the mornings following a full moon a good time to catch a daytime moon. Watch for it during the coming week, after sunrise, over your western horizon. It’ll appear pale against the blue sky. Thanks to what’s called the moon illusion, you might notice the daytime moon looking huge when close to the horizon.
The moon is up in the daytime half of the time. But, because it’s pale against the blue sky, it’s not as noticeable during the day as at night. Still, there are certain windows each month during which the daytime moon is most noticeable.
The coming week presents one of those windows. It’s a good time to watch for a daytime moon in the morning sky.
Then, the next last quarter moon will fall at 1:35 UTC on April 21, 2025. That’s 8:35 p.m. CDT on April 20. It’ll rise after midnight your local time and set around noon. Look for it high in the sky before dawn.
Daytime moon photos from the EarthSky community
View at EarthSky Community Photos. | Peter Lowenstein caught the daytime moon in its waning gibbous phase from Mutare, Zimbabwe. He said: “Three-quarters of an hour after sunrise, I photographed the daytime moon descending toward the top of a flowering African tulip (Spathodia campanulata) tree.” Thank you, Peter!View at EarthSky Community Photos. | Ragini Chaturvedi captured this image on November 14, 2022, in New Jersey. Ragini wrote: “Daytime moon basking in the morning sun, amidst the cold and windy start to the day.” Thank you, Ragini!A daytime moon on January 28, 2013 as seen by EarthSky Facebook friend Denise Johnson in Ridgecrest, California, in the Mojave Desert. Notice that this moon in this photo is closer to the (western) horizon at sunrise than the moon one day later (photo below). Full moon was January 27. Afterwards, the moon is waning again and inching closer to the sun on the sky’s dome.Waning gibbous moon in the west around the time of sunrise, as captured by EarthSky Facebook friend Royce Malacaman in the Philippiines. Thank you, Royce. View larger.Daytime moon – May 27, 2012 – Darren Danks in Netherton UK. See more moon photos at EarthSky’s Facebook page.Daytime moon of May 27, 2012, seen from Ireland. Photo by Damian O’Sullivan. Thank you, Damian! View larger.
Bottom line: You can easily spot the moon in the morning sky – after sunrise – for several days after full moon. Look west after the sun comes up! And a week after the full moon, look high in the sky after dawn.
