Can it ever be too cold to snow? A crack in Antarctica’s Pine Island Glacier. Image via NASA.
Can it be too cold to snow?
It rarely snows when the temperature drops below 0 degrees Fahrenheit (-18 degrees Celsius). So can it be too cold to snow? It can snow when it’s very cold. As a matter of fact, snow can fall even in the coldest places on Earth, such as Antarctica, where temperatures are well below zero.
It turns out snow is more a result of moisture than temperature.
When moist air rises and cools, the water starts to cling to floating particles of dust or pollen. If it’s cold enough, the water freezes into the complex ice crystals we call snowflakes. Generally, the colder it gets, the easier it is for snowflakes to form. If there’s enough water, the flakes can get large and the snow can fall.
View at EarthSky Community Photos. | Lorraine Boyd captured this image on March 23, 2024, in New York, and wrote: “Here in upstate New York, the morning began with rain, sleet, & ice. We ended up with a beautiful spring snowfall, anywhere from a couple of inches to 19 inches or so.” Thank you, Lorraine!
Moisture determines if snow reaches the ground
So it can’t be too cold to snow – but it can be too dry to snow. If it’s too dry, snow crystals may form – but there isn’t enough water left to build large flakes. So any flakes that do form are so small that they evaporate before reaching the ground. The colder it is – the faster all this happens – so it might seem too cold to snow.
No matter how cold a snow-producing cloud is, if it finds a new source of water, it can build big snowflakes again. That’s why Buffalo, New York is known for its snow. No matter how cold it gets there, the clouds can pick up water from nearby Lake Erie to make plenty of snow.
Bottom line: Can it ever be too cold to snow? The fact is, no matter how cold a snow-producing cloud is, if it has a source of water, it can build big snowflakes.
Can it ever be too cold to snow? A crack in Antarctica’s Pine Island Glacier. Image via NASA.
Can it be too cold to snow?
It rarely snows when the temperature drops below 0 degrees Fahrenheit (-18 degrees Celsius). So can it be too cold to snow? It can snow when it’s very cold. As a matter of fact, snow can fall even in the coldest places on Earth, such as Antarctica, where temperatures are well below zero.
It turns out snow is more a result of moisture than temperature.
When moist air rises and cools, the water starts to cling to floating particles of dust or pollen. If it’s cold enough, the water freezes into the complex ice crystals we call snowflakes. Generally, the colder it gets, the easier it is for snowflakes to form. If there’s enough water, the flakes can get large and the snow can fall.
View at EarthSky Community Photos. | Lorraine Boyd captured this image on March 23, 2024, in New York, and wrote: “Here in upstate New York, the morning began with rain, sleet, & ice. We ended up with a beautiful spring snowfall, anywhere from a couple of inches to 19 inches or so.” Thank you, Lorraine!
Moisture determines if snow reaches the ground
So it can’t be too cold to snow – but it can be too dry to snow. If it’s too dry, snow crystals may form – but there isn’t enough water left to build large flakes. So any flakes that do form are so small that they evaporate before reaching the ground. The colder it is – the faster all this happens – so it might seem too cold to snow.
No matter how cold a snow-producing cloud is, if it finds a new source of water, it can build big snowflakes again. That’s why Buffalo, New York is known for its snow. No matter how cold it gets there, the clouds can pick up water from nearby Lake Erie to make plenty of snow.
Bottom line: Can it ever be too cold to snow? The fact is, no matter how cold a snow-producing cloud is, if it has a source of water, it can build big snowflakes.
Firefly Aerospace plans to launch its Blue Ghost lunar lander in mid-January on a SpaceX Falcon 9 rocket. The mission will take 10 NASA science payloads to the moon. Image via Firefly Aerospace.
Blue Ghost to launch to the moon
Firefly Aerospace is a private company near Austin, Texas, that NASA contracted to take science payloads to the moon. Its Blue Ghost mission is scheduled to launch sometime in January on a SpaceX Falcon 9 rocket. This will be the first mission to the moon for the Blue Ghost lunar lander, and the company has dubbed mission number one Ghost Riders in the Sky. The lander is aiming for Mare Crisium, a dark plain you can see with the unaided eye on the right edge of a full moon.
Firefly Aerospace named the mission Blue Ghost after a type of rare firefly in the southeastern U.S. that has a unique blue glow.
Firefly expects Blue Ghost will launch from Kennedy Space Center in mid-January during a 6-day window. The mission will spend about 45 days getting to the moon. For the first 25 days, Blue Ghost will orbit Earth. Then it will head toward the moon, which should take approximately four days. It will then orbit the moon for 16 days. During transit, it will perform health checks and begin some of its science experiments. The lander will then reach the surface, where it will operate for 14 days.
Remember that on the moon, it takes 14 Earth days to go from sunrise to sunset. And then another 14 Earth days from sunset to sunrise. So when night descends on the lander, Firefly expects it to operate for the first five-plus hours of darkness before its solar-powered batteries run out.
View larger. | Here’s the route Blue Ghost will take as it heads toward its lunar landing. Image via Firefly Aerospace.
Science payloads
NASA will have 10 science payloads onboard Blue Ghost. Some of the tasks Blue Ghost has on the lunar surface will be to take soil samples, drill below the surface and capture images of the lunar sunset. NASA will also be testing a computer designed to withstand high doses of radiation, measuring the solar wind’s interaction with Earth’s magnetosphere and analyzing the pesky lunar dust that adheres to everything, among other activities.
NASA wants to learn more about the lunar environment before the Artemis astronauts make their first landing on the moon. That mission, Artemis 3, is currently scheduled for 2027.
Bottom line: Firefly Aerospace plans to launch Blue Ghost to the moon in mid-January. The mission will land on the moon and conduct science experiments for NASA before powering down when the long lunar night arrives.
Firefly Aerospace plans to launch its Blue Ghost lunar lander in mid-January on a SpaceX Falcon 9 rocket. The mission will take 10 NASA science payloads to the moon. Image via Firefly Aerospace.
Blue Ghost to launch to the moon
Firefly Aerospace is a private company near Austin, Texas, that NASA contracted to take science payloads to the moon. Its Blue Ghost mission is scheduled to launch sometime in January on a SpaceX Falcon 9 rocket. This will be the first mission to the moon for the Blue Ghost lunar lander, and the company has dubbed mission number one Ghost Riders in the Sky. The lander is aiming for Mare Crisium, a dark plain you can see with the unaided eye on the right edge of a full moon.
Firefly Aerospace named the mission Blue Ghost after a type of rare firefly in the southeastern U.S. that has a unique blue glow.
Firefly expects Blue Ghost will launch from Kennedy Space Center in mid-January during a 6-day window. The mission will spend about 45 days getting to the moon. For the first 25 days, Blue Ghost will orbit Earth. Then it will head toward the moon, which should take approximately four days. It will then orbit the moon for 16 days. During transit, it will perform health checks and begin some of its science experiments. The lander will then reach the surface, where it will operate for 14 days.
Remember that on the moon, it takes 14 Earth days to go from sunrise to sunset. And then another 14 Earth days from sunset to sunrise. So when night descends on the lander, Firefly expects it to operate for the first five-plus hours of darkness before its solar-powered batteries run out.
View larger. | Here’s the route Blue Ghost will take as it heads toward its lunar landing. Image via Firefly Aerospace.
Science payloads
NASA will have 10 science payloads onboard Blue Ghost. Some of the tasks Blue Ghost has on the lunar surface will be to take soil samples, drill below the surface and capture images of the lunar sunset. NASA will also be testing a computer designed to withstand high doses of radiation, measuring the solar wind’s interaction with Earth’s magnetosphere and analyzing the pesky lunar dust that adheres to everything, among other activities.
NASA wants to learn more about the lunar environment before the Artemis astronauts make their first landing on the moon. That mission, Artemis 3, is currently scheduled for 2027.
Bottom line: Firefly Aerospace plans to launch Blue Ghost to the moon in mid-January. The mission will land on the moon and conduct science experiments for NASA before powering down when the long lunar night arrives.
The bright star Capella in the constellation Auriga the Charioteer is a flashy star when close to the horizon. That’s because it’s bright at magnitude 0.24. To be sure you’ve found Capella, look for a little triangle of stars nearby. Capella is sometimes called the Goat Star, and the little triangle of stars is an asterism called The Kids.
Capella shines brightly on winter nights
The star Capella is prominent on Northern Hemisphere winter evenings. It’s also known as Alpha Aurigae because it’s the brightest star in the constellation Auriga the Charioteer. Capella is the northernmost star in the huge asterism, or star pattern, known as the Winter Hexagon, and the 6th-brightest star in our night sky.
Capella may look like one star, but it’s actually four stars. More about the Capella system below.
Capella – aka as the Goat Star – is the Latin word for nanny goat.
The point of light we see as Capella looks distinctly golden. And Capella shares spectral type – type G – with our sun. In fact, Capella is the biggest and brightest yellow star in our sky. It’s much bigger and brighter than our sun in absolute terms, and, of course, much farther away at a distance of about 42 light-years. That’s in contrast to our sun’s distance of 8 light-minutes.
Auriga as depicted in Urania’s Mirror, a set of constellation cards published in London circa 1825. Capella, the Goat Star, is a goat that the Charioteer carries on his shoulder. Notice the 2 baby goats – known as The Kids – at the larger goat’s feet. Image via Wikipedia.
From mid-latitudes of the U.S. and Europe, Capella is far enough to the north that it’s visible at some time of the night all year round. For those of us in the Northern Hemisphere, it’s best visible in winter, when you’ll find golden Capella high overhead before bedtime. In the autumn, when Capella is lower near the northeastern horizon and appearing through a thick layer of Earth’s atmosphere, the star twinkles brightly, flashing colors of red, blue and green.
Capella is the brightest star in a five-sided pentagonal shape that makes up the constellation Auriga the Charioteer. The shape is difficult to reconcile with the idea of a man driving a chariot, but it’s a noticeable pattern and easy to find.
Here is the key to knowing you’ve found Capella. Near it, you’ll find a tiny asterism – a noticeable pattern on the sky’s dome – consisting of three fainter stars. This little triangle of stars is The Kids, and it makes Capella instantly recognizable.
Like so many stars that appear single to the eye, Capella is a quadruple star system consisting of two binary stars.
The A star in the Capella system is what’s called a spectroscopic binary. That is, although the two stars are so close that a normal telescope cannot separate them, their different light signatures, as astronomers can see using spectroscopy, “splits” the star, thereby recognizing it as two stars. Both Capella Aa and Capella Ab, as they’re called, have roughly 10 times our sun’s diameter. They emit about 80 and 50 times more overall light than our sun, respectively. Casual observers will not be able to separate these stars through backyard telescopes.
Capella Aa and Ab are both yellow giant stars at the end of their normal lifetimes. Because each star is about 2 1/2 times more massive than our sun, the two components of Capella likely are also younger. This is because more massive stars have higher internal pressures, which causes them to burn their nuclear fuel faster and to have shorter lifespans. The two stars of Capella are in a transitional period from the smaller, hotter stars they once were, to the cooler and larger red giants they must ultimately become in their final phase. However, for now, their surface temperatures fall in the range of spectral type G.
The secondary pair, Capella H and Capella L, are small and cool red dwarfs. They are about 10,000 astronomical units (AU) from the first pair.
Astronomers measure the combined magnitude of this system as 0.08.
Artist’s concept of the 2 primary stars in the Capella system, known as Capella Aa and Capella Ab. They’re shown here with their sizes in contrast to our sun (labeled Sol in this image), and the other 2 components, Capella H and L. Image via Wikimedia Commons.
History and mythology of Auriga’s brightest star
For such a large constellation with such a bright star, the mythology of Auriga and Capella is sparse. The constellation has been associated with the Greek sea god Poseidon (the Roman god Neptune). Other stories say Auriga represents Erichthonius, the ancient lame king of Athens who invented the horse-drawn chariot.
Auriga seems to have been associated with shepherds and flocks, so the title of nanny goat – “she-goat” – for Capella is reasonable. However, neither Capella nor its constellation Auriga figures prominently in any major mythological stories from Greek or Roman culture.
Richard Hinkley Allen, in his famed Star Names, says that the ancient Arabs called the star Capella by a name that meant “The Driver” and implies that this star was a shepherd driving a flock across the sky. The flock might have been the nearby star cluster the Pleiades, although – instead of sheep or goats – early Arabian stargazers saw this pattern composed of camels. Capella was also apparently important in ancient Egypt. It appears on the Dendera Zodiac as a mummified cat.
In China, Capella and four other stars of Auriga were known as the Five Chariots. The other four stars are Auriga’s Beta, Theta, Kappa and Gamma (El Nath, which is now Beta Tauri).
Capella’s position is RA: 5h 16m 41.4s, Dec: +45° 59′ 53″.
Bottom line: Capella, the Goat Star, is the brightest star in the constellation Auriga the Charioteer and the sixth brightest star in the night sky. Capella is prominent in the Northern Hemisphere’s winter sky and makes up one of the points in the Winter Hexagon.
The bright star Capella in the constellation Auriga the Charioteer is a flashy star when close to the horizon. That’s because it’s bright at magnitude 0.24. To be sure you’ve found Capella, look for a little triangle of stars nearby. Capella is sometimes called the Goat Star, and the little triangle of stars is an asterism called The Kids.
Capella shines brightly on winter nights
The star Capella is prominent on Northern Hemisphere winter evenings. It’s also known as Alpha Aurigae because it’s the brightest star in the constellation Auriga the Charioteer. Capella is the northernmost star in the huge asterism, or star pattern, known as the Winter Hexagon, and the 6th-brightest star in our night sky.
Capella may look like one star, but it’s actually four stars. More about the Capella system below.
Capella – aka as the Goat Star – is the Latin word for nanny goat.
The point of light we see as Capella looks distinctly golden. And Capella shares spectral type – type G – with our sun. In fact, Capella is the biggest and brightest yellow star in our sky. It’s much bigger and brighter than our sun in absolute terms, and, of course, much farther away at a distance of about 42 light-years. That’s in contrast to our sun’s distance of 8 light-minutes.
Auriga as depicted in Urania’s Mirror, a set of constellation cards published in London circa 1825. Capella, the Goat Star, is a goat that the Charioteer carries on his shoulder. Notice the 2 baby goats – known as The Kids – at the larger goat’s feet. Image via Wikipedia.
From mid-latitudes of the U.S. and Europe, Capella is far enough to the north that it’s visible at some time of the night all year round. For those of us in the Northern Hemisphere, it’s best visible in winter, when you’ll find golden Capella high overhead before bedtime. In the autumn, when Capella is lower near the northeastern horizon and appearing through a thick layer of Earth’s atmosphere, the star twinkles brightly, flashing colors of red, blue and green.
Capella is the brightest star in a five-sided pentagonal shape that makes up the constellation Auriga the Charioteer. The shape is difficult to reconcile with the idea of a man driving a chariot, but it’s a noticeable pattern and easy to find.
Here is the key to knowing you’ve found Capella. Near it, you’ll find a tiny asterism – a noticeable pattern on the sky’s dome – consisting of three fainter stars. This little triangle of stars is The Kids, and it makes Capella instantly recognizable.
Like so many stars that appear single to the eye, Capella is a quadruple star system consisting of two binary stars.
The A star in the Capella system is what’s called a spectroscopic binary. That is, although the two stars are so close that a normal telescope cannot separate them, their different light signatures, as astronomers can see using spectroscopy, “splits” the star, thereby recognizing it as two stars. Both Capella Aa and Capella Ab, as they’re called, have roughly 10 times our sun’s diameter. They emit about 80 and 50 times more overall light than our sun, respectively. Casual observers will not be able to separate these stars through backyard telescopes.
Capella Aa and Ab are both yellow giant stars at the end of their normal lifetimes. Because each star is about 2 1/2 times more massive than our sun, the two components of Capella likely are also younger. This is because more massive stars have higher internal pressures, which causes them to burn their nuclear fuel faster and to have shorter lifespans. The two stars of Capella are in a transitional period from the smaller, hotter stars they once were, to the cooler and larger red giants they must ultimately become in their final phase. However, for now, their surface temperatures fall in the range of spectral type G.
The secondary pair, Capella H and Capella L, are small and cool red dwarfs. They are about 10,000 astronomical units (AU) from the first pair.
Astronomers measure the combined magnitude of this system as 0.08.
Artist’s concept of the 2 primary stars in the Capella system, known as Capella Aa and Capella Ab. They’re shown here with their sizes in contrast to our sun (labeled Sol in this image), and the other 2 components, Capella H and L. Image via Wikimedia Commons.
History and mythology of Auriga’s brightest star
For such a large constellation with such a bright star, the mythology of Auriga and Capella is sparse. The constellation has been associated with the Greek sea god Poseidon (the Roman god Neptune). Other stories say Auriga represents Erichthonius, the ancient lame king of Athens who invented the horse-drawn chariot.
Auriga seems to have been associated with shepherds and flocks, so the title of nanny goat – “she-goat” – for Capella is reasonable. However, neither Capella nor its constellation Auriga figures prominently in any major mythological stories from Greek or Roman culture.
Richard Hinkley Allen, in his famed Star Names, says that the ancient Arabs called the star Capella by a name that meant “The Driver” and implies that this star was a shepherd driving a flock across the sky. The flock might have been the nearby star cluster the Pleiades, although – instead of sheep or goats – early Arabian stargazers saw this pattern composed of camels. Capella was also apparently important in ancient Egypt. It appears on the Dendera Zodiac as a mummified cat.
In China, Capella and four other stars of Auriga were known as the Five Chariots. The other four stars are Auriga’s Beta, Theta, Kappa and Gamma (El Nath, which is now Beta Tauri).
Capella’s position is RA: 5h 16m 41.4s, Dec: +45° 59′ 53″.
Bottom line: Capella, the Goat Star, is the brightest star in the constellation Auriga the Charioteer and the sixth brightest star in the night sky. Capella is prominent in the Northern Hemisphere’s winter sky and makes up one of the points in the Winter Hexagon.
Los Angeles fires from space, January 7, 2025. As of this morning, a state of emergency remains in effect for Los Angeles city and county as at least 4 fires continue to burn out of control. They are the most destructive ever to hit Los Angeles County. Historically dry and windy conditions contributed to the wildfires. There have been 5 deaths so far. Evacuation efforts have been hampered by snarled traffic, as masses of people attempt to flee. Nearly 2,000 homes and buildings have been destroyed and nearly 400,000 homes and businesses have lost power. NASA Earth Observatory published this image on January 8, 2025.
Multiple destructive fires broke out in the hills of Los Angeles County in early January 2025. As of January 8, several major wildland fires burned, fueled by a dry landscape and winds that gusted up to 100 miles per hour. The blazes have destroyed thousands of structures and prompted officials to issue evacuation orders in several parts of the county.
One of the wind-driven fires ignited during the morning of January 7, near the Pacific Palisades neighborhood. The image below, acquired by the European Space Agency’s Sentinel-2 satellite, shows the Palisades fire at 10:45 a.m. Pacific Time on January 7, soon after it ignited.
Smoke continued to stream from the Palisades fire toward the Pacific Ocean that afternoon, when the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua satellite captured the image above. By the afternoon of January 8, it had moved westward along the Pacific Coast Highway toward Malibu, scorching over 11,000 acres (44 square kilometers), according to Cal Fire.
Farther inland, the Eaton fire erupted on the evening of January 7 in Altadena, north of downtown Los Angeles. The fire quickly spread to more than 10,000 acres (40 square kilometers), burning parts of Pasadena and Altadena. Another major fire, Hurst, broke out in San Fernando the night of January 7.
Powerful Santa Ana winds and a lack of rain created “critical” fire weather conditions in Southern California, according to the National Weather Service. Santa Ana winds typically occur between October and January when a pressure gradient builds up between the Great Basin to the east and the cool Pacific Ocean to the west. The weather pattern sends gusty, dry winds streaming down the side of inland mountain ranges, through narrow mountain canyons, and toward the coast.
Although windy conditions are typical this time of year, a lack of rain contributed to the dangerous fire weather. Since October, Southern California has received negligible rain, and according to climate scientist Daniel Swain, the region has experienced the driest start to the winter on record. The Los Angeles airport, for example, recorded 0.03 inches (0.08 centimeters) of rain since October 1 -the start of the water year in the state – making it the area’s driest start to the water year on a record maintained by the National Weather Service dating back to 1944.
According to the National Weather Service in Los Angeles, dangerous fire conditions were expected to persist through the evening of January 8 and into January 9.
View at EarthSky Community Photos. | Laurie Engelhardt in Hermosa Beach, California, shared this image on January 8, 2025, and wrote: “Fiery sunset closing out a very tumultuous day in California.” Thank you, Laurie!
Bottom line: Crews continued battling the Los Angeles fires overnight on Wednesday. They are the most destructive fires in the history of Los Angeles County.
Los Angeles fires from space, January 7, 2025. As of this morning, a state of emergency remains in effect for Los Angeles city and county as at least 4 fires continue to burn out of control. They are the most destructive ever to hit Los Angeles County. Historically dry and windy conditions contributed to the wildfires. There have been 5 deaths so far. Evacuation efforts have been hampered by snarled traffic, as masses of people attempt to flee. Nearly 2,000 homes and buildings have been destroyed and nearly 400,000 homes and businesses have lost power. NASA Earth Observatory published this image on January 8, 2025.
Multiple destructive fires broke out in the hills of Los Angeles County in early January 2025. As of January 8, several major wildland fires burned, fueled by a dry landscape and winds that gusted up to 100 miles per hour. The blazes have destroyed thousands of structures and prompted officials to issue evacuation orders in several parts of the county.
One of the wind-driven fires ignited during the morning of January 7, near the Pacific Palisades neighborhood. The image below, acquired by the European Space Agency’s Sentinel-2 satellite, shows the Palisades fire at 10:45 a.m. Pacific Time on January 7, soon after it ignited.
Smoke continued to stream from the Palisades fire toward the Pacific Ocean that afternoon, when the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua satellite captured the image above. By the afternoon of January 8, it had moved westward along the Pacific Coast Highway toward Malibu, scorching over 11,000 acres (44 square kilometers), according to Cal Fire.
Farther inland, the Eaton fire erupted on the evening of January 7 in Altadena, north of downtown Los Angeles. The fire quickly spread to more than 10,000 acres (40 square kilometers), burning parts of Pasadena and Altadena. Another major fire, Hurst, broke out in San Fernando the night of January 7.
Powerful Santa Ana winds and a lack of rain created “critical” fire weather conditions in Southern California, according to the National Weather Service. Santa Ana winds typically occur between October and January when a pressure gradient builds up between the Great Basin to the east and the cool Pacific Ocean to the west. The weather pattern sends gusty, dry winds streaming down the side of inland mountain ranges, through narrow mountain canyons, and toward the coast.
Although windy conditions are typical this time of year, a lack of rain contributed to the dangerous fire weather. Since October, Southern California has received negligible rain, and according to climate scientist Daniel Swain, the region has experienced the driest start to the winter on record. The Los Angeles airport, for example, recorded 0.03 inches (0.08 centimeters) of rain since October 1 -the start of the water year in the state – making it the area’s driest start to the water year on a record maintained by the National Weather Service dating back to 1944.
According to the National Weather Service in Los Angeles, dangerous fire conditions were expected to persist through the evening of January 8 and into January 9.
View at EarthSky Community Photos. | Laurie Engelhardt in Hermosa Beach, California, shared this image on January 8, 2025, and wrote: “Fiery sunset closing out a very tumultuous day in California.” Thank you, Laurie!
Bottom line: Crews continued battling the Los Angeles fires overnight on Wednesday. They are the most destructive fires in the history of Los Angeles County.
Nick Mott and Justin Angle have written a new book, called This Is Wildfire: How to Protect Yourself, Your Home and Your Community in the Age of Heat. It looks at how historical management practices have led to a problematic fire landscape. It talks about how wildfires affect people and communities, and suggests a way forward. Plus, the book provides checklists for homeowners.
So, are the numbers of wildfires increasing? As the book explains:
It’s not that we’re seeing drastically more fires than ever before … the data show that the number of fire starts each year varies widely, but isn’t changing significantly in one way or the other.
[But] more and more of these fires are ripping out of control into enormous, destructive conflagrations.
Why are fires so much bigger and more destructive now? First, past policy has been to extinguish all fires, leading to unhealthy forests. Second, we’ve developed more land father from cities, spreading out into areas that burn more easily. And third, we live in a warming world, with greater heat and climate-induced drought.
This Is Wildfire by Nick Mott and Justin Angle explains the history of wildfire and instructs individuals and communities on how to protect themselves from wildfire. Image via Bloomsbury.
Preparing your home for wildfire
One insight the book shared that I found particularly eye-opening was that:
firefighters will drive right past homes that are likely to burn.
It may sound harsh, but it makes sense. As a fire rolls into a community, firefighters cannot waste time on homes that are not hardened against wildfire. They need to prioritize buildings that have the best chance to survive the fire. So, what do you have to do to set your home up for the best odds of surviving a wildfire? Prepare the home ignition zone, or the 100 feet (30 meters) surrounding your home. This zone is broken down into three areas:
The immediate zone is the land zero to five feet from your house. You’ll want to clean your roof and eaves and repair siding where flames can easily get in. Hardscape your landscaping around the home. Replace mulch with rocks. Trim trees to keep them from your home. And store vehicles such as lawn mowers or ATVs farther from the house.
The intermediate zone is five to 30 feet (9 meters) from your house. In this zone you want to keep grass four inches or shorter. Remove ladder fuels (vegetation that can lift flames) and landscape with breaks (avoid clustering shrubs, etc). The crowns of trees should be 18 feet or more apart. Bury propane tanks.
The extended zone is 30 to 100 feet (9 to 30 meters) from your house. In this area, you’re trying to slow a fire down. Remove piles of debris. Removing small trees and having gaps between plantings is important to keep the fire from easily spreading. See the graphic below for more.
This Is Wildfire home preparation
This illustration from the book This Is Wildfire shows how to prepare your home to survive a wildfire. The left side of the illustration is a house not prepared, while the right side shows a house that is ready for wildfire season. Image via Jessy Stevenson/ This Is Wildfire. Used with permission.
Preparing yourself for wildfire
Imagine a wildfire is approaching. You want to be prepared to move to safety even before the evacuation notice comes in. So, you need a go bag. Have it handy near the door so you can grab it in a rush. And review the contents once a year to refresh items like food and medication.
Some key items for a go-bag can include a sturdy pair of shoes, leather work gloves, goggles, N95 masks, a map, prescription medications, water
bottles, energy bars, spare phone battery, keys and credit cards, a first aid kit, headlamp, a spare toothbrush and toothpaste, personal hygiene items and pet supplies. Add the things that might help keep you sane in the event of an emergency: maybe a pack of playing cards, headphones, a favorite book.
This illustration from the book This Is Wildfire shows items you might want to store in a go bag, so that you can leave your house quickly in case of an approaching wildfire. Image via Jessy Stevenson/ This Is Wildfire. Used with permission.
Find more tips to keep safe and to organize your community in This Is Wildfire.
Bottom line: The book This Is Wildfire explains why wildfires seem larger and more destructive. Find tips on preparing yourself, your home and your community for wildfire.
Nick Mott and Justin Angle have written a new book, called This Is Wildfire: How to Protect Yourself, Your Home and Your Community in the Age of Heat. It looks at how historical management practices have led to a problematic fire landscape. It talks about how wildfires affect people and communities, and suggests a way forward. Plus, the book provides checklists for homeowners.
So, are the numbers of wildfires increasing? As the book explains:
It’s not that we’re seeing drastically more fires than ever before … the data show that the number of fire starts each year varies widely, but isn’t changing significantly in one way or the other.
[But] more and more of these fires are ripping out of control into enormous, destructive conflagrations.
Why are fires so much bigger and more destructive now? First, past policy has been to extinguish all fires, leading to unhealthy forests. Second, we’ve developed more land father from cities, spreading out into areas that burn more easily. And third, we live in a warming world, with greater heat and climate-induced drought.
This Is Wildfire by Nick Mott and Justin Angle explains the history of wildfire and instructs individuals and communities on how to protect themselves from wildfire. Image via Bloomsbury.
Preparing your home for wildfire
One insight the book shared that I found particularly eye-opening was that:
firefighters will drive right past homes that are likely to burn.
It may sound harsh, but it makes sense. As a fire rolls into a community, firefighters cannot waste time on homes that are not hardened against wildfire. They need to prioritize buildings that have the best chance to survive the fire. So, what do you have to do to set your home up for the best odds of surviving a wildfire? Prepare the home ignition zone, or the 100 feet (30 meters) surrounding your home. This zone is broken down into three areas:
The immediate zone is the land zero to five feet from your house. You’ll want to clean your roof and eaves and repair siding where flames can easily get in. Hardscape your landscaping around the home. Replace mulch with rocks. Trim trees to keep them from your home. And store vehicles such as lawn mowers or ATVs farther from the house.
The intermediate zone is five to 30 feet (9 meters) from your house. In this zone you want to keep grass four inches or shorter. Remove ladder fuels (vegetation that can lift flames) and landscape with breaks (avoid clustering shrubs, etc). The crowns of trees should be 18 feet or more apart. Bury propane tanks.
The extended zone is 30 to 100 feet (9 to 30 meters) from your house. In this area, you’re trying to slow a fire down. Remove piles of debris. Removing small trees and having gaps between plantings is important to keep the fire from easily spreading. See the graphic below for more.
This Is Wildfire home preparation
This illustration from the book This Is Wildfire shows how to prepare your home to survive a wildfire. The left side of the illustration is a house not prepared, while the right side shows a house that is ready for wildfire season. Image via Jessy Stevenson/ This Is Wildfire. Used with permission.
Preparing yourself for wildfire
Imagine a wildfire is approaching. You want to be prepared to move to safety even before the evacuation notice comes in. So, you need a go bag. Have it handy near the door so you can grab it in a rush. And review the contents once a year to refresh items like food and medication.
Some key items for a go-bag can include a sturdy pair of shoes, leather work gloves, goggles, N95 masks, a map, prescription medications, water
bottles, energy bars, spare phone battery, keys and credit cards, a first aid kit, headlamp, a spare toothbrush and toothpaste, personal hygiene items and pet supplies. Add the things that might help keep you sane in the event of an emergency: maybe a pack of playing cards, headphones, a favorite book.
This illustration from the book This Is Wildfire shows items you might want to store in a go bag, so that you can leave your house quickly in case of an approaching wildfire. Image via Jessy Stevenson/ This Is Wildfire. Used with permission.
Find more tips to keep safe and to organize your community in This Is Wildfire.
Bottom line: The book This Is Wildfire explains why wildfires seem larger and more destructive. Find tips on preparing yourself, your home and your community for wildfire.
A team of scientists has discovered a new species of moray eel in river mouths of the Central Indo-Pacific. Interestingly, this discovery has a peculiarity, as moray eels usually live in saltwater, not in estuarine habitats, that is, in places where rivers meet the sea. The international team of scientists that discovered the animal nicknamed this striking species after the god of the underworld: Hades. This moray eel has a dark coloration, inhabits turbid waters with muddy and soft substrates and is highly sensitive to light. The scientists announced their discovery on December 31, 2024.
Scientists Wen-Chien Huang and Te-Yu Liao of the National Sun Yat-sen University in Taiwan, Rodulf Anthony Balisco of the Western Philippines University and Yusuke Hibino of the Kitakyushu Museum of Natural History and Human History in Japan describe this new moray eel in their peer-reviewed study, published in the open-access journal ZooKeys.
This discovery is striking for the location where the scientists found the moray eel, the eel’s appearance and its behavior. Overall, there are 230 species of moray eel worldwide. And almost all of them live in seawater. The number of species that can tolerate a lower level of salinity and can adapt to estuarine (partly salt water, partly fresh water) habitats is extremely rare.
The team of scientists was investigating the underground river cave of Puerto Princesa in the Philippines, with the aim of studying the aquatic fauna. The intention was to study a cave eel species, the bean-eyed snake moray (Uropterygius cyamommatus). As its name suggests, this moray eel has very small eyes. This makes it a good candidate for studying the evolutionary processes that allow moray eels to adapt to cave environments.
But the researchers didn’t find any of the cave eel species, however. Instead, they collected a moray eel with a striking, intense, uniform dark color. This is the moray now known as Hades’ snake moray (Uropterygius Hades).
The newly discovered species of moray eel possesses a striking, intense, uniform dark color. Here, the image at the top shows a male and the image at the bottom a female. Image via Wen-Chien Huang/ ZooKeys.
Habitat and behavior of the Hades moray eel
According to the study, the Hades species prefers turbid waters in estuarine habitats and muddy substrates. With this in mind, here’s one peculiar behavior. When it digs to hide, this eel does so by starting with its tail. Indeed, this is a rare behavior in moray eels. The scientists said:
Combining information from habitat type, body structure and behavior, we propose that U. Hades is an estuarine moray eel that inhabits turbid waters with muddy and soft substrates, using its tail to burrow and hide in sediments, among rocks or in fallen mangrove leaves.
On the other hand, this eel has fewer sensory pores on its head, and that fact might help the eel be an excellent digger. The scientists explained:
The reduction in the number of head pores is hypothesized to help avoid clogging by the substrate, as this phenomenon is observed in certain eel species that inhabit sand and mud burrows.
Furthermore, when the scientist kept the species in an aquatic tank, they observed that the animal is very sensitive to light and always tries to hide from it. In fact, the researchers think its small eyes are an adaptation to low-light environments. They said:
The small eye proportion of U. Hades may also indicate its adaptation to low-light conditions, wherein they primarily use their chemoreception rather than vision to detect prey or avoid predators.
The Hades species inhabits estuarine habitats, prefers muddy substrates, has small eyes and is very sensitive to light. The arrows indicate the position of the anus. Image via Wen-Chien Huang/ ZooKeys.
The new animal god of the underworld
This slender, dark moray eel has thrived in the dark, muddy mouths of rivers, unlike most of its marine moray relatives. The Hades species is widely distributed across the Central Indo-Pacific and has been found in southern Japan, Taiwan, the Philippines, southern Java and Fiji.
Huang chose the name after Hades, the god of the underworld, to emphasize its imposing appearance and habitat in dark, turbid environments. I couldn’t have come up with a better name myself!
Different habitats of Uropterygius Hades. A) Oura River, Okinawa Island, photographed by Koki Takatsuki. B) Live photo of a U. Hades hiding in gaps among mangrove aerial roots, taken at night at the edge of a mangrove forest zone along the Oura River, Okinawa Island, photographed by Hirozumi Kobayashi. C) Puerto Princesa subterranean river, Palawan, photographed by Wei-Cheng Jhuang. D) Zhuan River, northeastern Taiwan, photographed by Shan-Yu Yang. Image via ZooKeys.
Bottom line: A moray eel has been discovered and named after the god of the underworld: Hades. This species inhabits estuarine habitats, prefers turbid waters and muddy substrates and hides from the light.
A team of scientists has discovered a new species of moray eel in river mouths of the Central Indo-Pacific. Interestingly, this discovery has a peculiarity, as moray eels usually live in saltwater, not in estuarine habitats, that is, in places where rivers meet the sea. The international team of scientists that discovered the animal nicknamed this striking species after the god of the underworld: Hades. This moray eel has a dark coloration, inhabits turbid waters with muddy and soft substrates and is highly sensitive to light. The scientists announced their discovery on December 31, 2024.
Scientists Wen-Chien Huang and Te-Yu Liao of the National Sun Yat-sen University in Taiwan, Rodulf Anthony Balisco of the Western Philippines University and Yusuke Hibino of the Kitakyushu Museum of Natural History and Human History in Japan describe this new moray eel in their peer-reviewed study, published in the open-access journal ZooKeys.
This discovery is striking for the location where the scientists found the moray eel, the eel’s appearance and its behavior. Overall, there are 230 species of moray eel worldwide. And almost all of them live in seawater. The number of species that can tolerate a lower level of salinity and can adapt to estuarine (partly salt water, partly fresh water) habitats is extremely rare.
The team of scientists was investigating the underground river cave of Puerto Princesa in the Philippines, with the aim of studying the aquatic fauna. The intention was to study a cave eel species, the bean-eyed snake moray (Uropterygius cyamommatus). As its name suggests, this moray eel has very small eyes. This makes it a good candidate for studying the evolutionary processes that allow moray eels to adapt to cave environments.
But the researchers didn’t find any of the cave eel species, however. Instead, they collected a moray eel with a striking, intense, uniform dark color. This is the moray now known as Hades’ snake moray (Uropterygius Hades).
The newly discovered species of moray eel possesses a striking, intense, uniform dark color. Here, the image at the top shows a male and the image at the bottom a female. Image via Wen-Chien Huang/ ZooKeys.
Habitat and behavior of the Hades moray eel
According to the study, the Hades species prefers turbid waters in estuarine habitats and muddy substrates. With this in mind, here’s one peculiar behavior. When it digs to hide, this eel does so by starting with its tail. Indeed, this is a rare behavior in moray eels. The scientists said:
Combining information from habitat type, body structure and behavior, we propose that U. Hades is an estuarine moray eel that inhabits turbid waters with muddy and soft substrates, using its tail to burrow and hide in sediments, among rocks or in fallen mangrove leaves.
On the other hand, this eel has fewer sensory pores on its head, and that fact might help the eel be an excellent digger. The scientists explained:
The reduction in the number of head pores is hypothesized to help avoid clogging by the substrate, as this phenomenon is observed in certain eel species that inhabit sand and mud burrows.
Furthermore, when the scientist kept the species in an aquatic tank, they observed that the animal is very sensitive to light and always tries to hide from it. In fact, the researchers think its small eyes are an adaptation to low-light environments. They said:
The small eye proportion of U. Hades may also indicate its adaptation to low-light conditions, wherein they primarily use their chemoreception rather than vision to detect prey or avoid predators.
The Hades species inhabits estuarine habitats, prefers muddy substrates, has small eyes and is very sensitive to light. The arrows indicate the position of the anus. Image via Wen-Chien Huang/ ZooKeys.
The new animal god of the underworld
This slender, dark moray eel has thrived in the dark, muddy mouths of rivers, unlike most of its marine moray relatives. The Hades species is widely distributed across the Central Indo-Pacific and has been found in southern Japan, Taiwan, the Philippines, southern Java and Fiji.
Huang chose the name after Hades, the god of the underworld, to emphasize its imposing appearance and habitat in dark, turbid environments. I couldn’t have come up with a better name myself!
Different habitats of Uropterygius Hades. A) Oura River, Okinawa Island, photographed by Koki Takatsuki. B) Live photo of a U. Hades hiding in gaps among mangrove aerial roots, taken at night at the edge of a mangrove forest zone along the Oura River, Okinawa Island, photographed by Hirozumi Kobayashi. C) Puerto Princesa subterranean river, Palawan, photographed by Wei-Cheng Jhuang. D) Zhuan River, northeastern Taiwan, photographed by Shan-Yu Yang. Image via ZooKeys.
Bottom line: A moray eel has been discovered and named after the god of the underworld: Hades. This species inhabits estuarine habitats, prefers turbid waters and muddy substrates and hides from the light.
View larger. | Perspective view from Mars Express of the transition region between Acidalia Planitia and Tempe Terra in the northern hemisphere of Mars. A new study suggests that the deep subsurface beneath Acidalia Planitia might be the best place to search for Martian life, existing in the form of methane-belching microbes on Mars. Image via ESA/ DLR/ FU Berlin/ G. Neukum (CC BY-SA 3.0 IGO).
Is there life on Mars? If so, it is likely microbial and deep below the surface, where temperatures are warmer and it is protected from the harsh surface conditions.
The best place to search is beneath a vast plain called Acidalia Planitia, in the northern hemisphere, according to a new study from Spain.
Any microbes there might be methanogens, organisms that expel methane as a byproduct. They might help explain the puzzling mystery of methane in Mars’ atmosphere.
Are there microbes on Mars?
Does life exist anywhere on Mars today? Mars’ surface is extremely cold, with a whisper-thin atmosphere and harsh radiation coming from the sun. But some scientists think living microbes might survive deep below the surface of Mars. And now, researchers in Spain say they’ve identified the best place to search: Acidalia Planitia, a vast plain in Mars’ northern hemisphere. The researchers said that microbes on Mars would most likely be methanogens, which are also found on Earth, and which leave behind methane as a byproduct. It’s a scenario that might help explain the mysterious presence of small amounts of methane in Mars’ atmosphere.
Astrophysicist Paul M. Sutter wrote about the news in Universe Today on December 21, 2024. The researchers submitted their peer-reviewed paper to the journal Astrobiology on November 22, 2024. A preprint version is also available on arXiv.
Andrea Butturini at the University of Barcelona in Spain led the new study. The research team looked for locations on Earth that could be analogs for the Martian environment. These are also places where methanogens exist. Methanogens are anaerobic (requiring an absence of free oxygen, that is, oxygen that is not a part of a compound) archaea that produce methane as a byproduct of their metabolism. The researchers found three kinds of locations that were analogous to Mars. As Sutter wrote in Universe Today:
The researchers found three potential Mars-like conditions on Earth where methanogens make a home. The first is deep in the crust, sometimes to a depth of several kilometers, where tiny cracks in rocks allow for liquid water to seep in. The second is lakes buried under the Antarctic polar ice cap, which maintain their liquid state thanks to the immense pressures of the ice above them. And the last is super-saline, oxygen-deprived basins in the deep ocean.
Earthly analogs where methanogens thrive
Those kinds of conditions also exist on Mars. So, could methanogenic-types microbes live there?
On Earth, the researchers mapped out the analog locations. They measured temperature ranges, salinity (salt) levels and pH values (acidity). In addition, they measured the abundance of molecular hydrogen at those locations. With all the data, the research team determined specifically where methanogens were most abundant.
Then, the data were compared to data from Mars, to find which locations on Mars were the most similar to those on Earth where methanogens thrived. One region in particular stood out: Acidalia Planitia. This is a vast plain in the northern hemisphere of Mars. It is a geologically rich region, with evidence for past hot springs, steam vents, glaciers and even possible mud volcanoes and oceans.
Here, conditions are the most similar to the Earthly analogs. Not on the surface, but rather below it. Several miles deep, in fact.
Acidalia Planitia, by the way, was the landing region for the human mission to Mars in both the book and movie “The Martian.”
This image in the Acidalia Planitia region of Mars shows numerous round hills that have a large circular depression on their tops. These pitted mounds may be ancient mud volcanoes.https://t.co/148A3dTnRJ
NASA/JPL-Caltech/UArizona#Marspic.twitter.com/r9zZMusGw5
— HiRISE: Beautiful Mars (NASA) (@HiRISE) July 19, 2023
Acidalia Planitia, the best place for life on Mars?
The intense debate about the presence of methane in the Martian atmosphere has stimulated the study of methanogens adapted to terrestrial habitats that mimic Martian environments. We examinate the environmental conditions, energy sources and ecology of terrestrial methanogens thriving in deep crystalline fractures, sub-sea hypersaline lakes and subglacial water bodies considered as analogs of a hypothetical habitable Martian subsurface.
We combine this information with recent data on the distribution of buried water or ice and radiogenic elements on Mars and with models of the subsurface thermal regime of this planet to identify a 4.3-8.8 km-deep [2.6-5.4 miles] regolith habitat at the mid-latitude location of Acidalia Planitia, that might fit the requirements for hosting putative Martian methanogens analogous to the methanogenic families Methanosarcinaceae and Methanomicrobiaceae.
The paper concluded:
As a result, both our analysis (which builds upon recent advances in understanding Mars’ subsurface) and previous research more focused on its surface converge in identifying the southern of Acidalia Planitia as a promising target area for future missions in the search for extant life in Mars’ subsurface.
Still a challenging environment
Even though conditions beneath the surface in Acidalia Planitia are far better than on the surface, it would still be a challenging environment for microbial life. As the paper noted:
Methanogens are significant, but not ubiquitous, in the microbial ecosystems thriving in the subsurface ecosystems believed to be terrestrial analogs of the Martian subsurface. Thus, although methanogens feed on simple molecules and their metabolism can be described by straightforward redox equations – making them ideal models for astrobiologists – studies of terrestrial deep temperate-hot crystalline fractures are revealing that these habitats are challenging for methanogens. Consequently, the cold Martian subsurface is likely an even harsher habitat for putative terrestrial-like methanogens.
Beyond the need for water, appropriate environmental conditions, and adequate energetic and carbon resources, the proliferation of methanogens also depends on complex ecological constraints. Indeed, methanogens establish ecological and energetic interactions with organisms with diverse metabolisms, suggesting that the conjecture that they might form mono-specific communities does not fit with what is regularly observed in terrestrial subsurface ecosystems. So, if terrestrial-like methanogens were to thrive in Mars’ subsurface, they would most likely be members of a complex and diverse ecosystem.
View larger. | Scientists have hypothesized several explanations for how methane is created, and then destroyed, in Mars’ atmosphere. Currently, the consensus is that it most likely originates underground. Methanogenic microbes are one of the possibilities. Image via ESA.
The subsurface of the southern of Acidalia Planitia is a putative target region for hosting cold-adapted Methanosarcinaceae-like and/or Methanomicrobiaceae-like methanogens (if they can associate with bacteria-like organisms). In this region, the radiogenic heat-producing elements are at the highest abundance and subsurface water is likely. Thus, water radiolysis could supply the energetic resources required for these hypothetical methanogens.
Our knowledge of Mars’ subsurface is advancing thanks to orbiters, landers and rovers, but critical gaps exist. To make substantial progress in identifying habitable niches in the subsurface of Mars, it will be essential to elucidate the availability of inorganic carbon in the subsurface, and to determine more accurately the depth at which water is located and the porosity/fracturing of the regolith, as these factors directly affect the thermal gradients and the efficiency of water radiolysis.
Needless to say, actually finding any evidence for microbes that far below the Martian surface will be difficult. Even now, rovers can only drill a matter of inches – or a few feet as with the upcoming ExoMars rover – into the ground or rocks. But perhaps another future mission will be able to analyze the puzzling methane emissions even closer, and determine whether they have a biological or non-biological source. That could reveal the existence of the hypothetical methanogens without having to dig at all.
Bottom line: A new study suggests that microbes on Mars might exist deep below the surface, and in one region in particular. They might even explain Martian mysterious methane.
View larger. | Perspective view from Mars Express of the transition region between Acidalia Planitia and Tempe Terra in the northern hemisphere of Mars. A new study suggests that the deep subsurface beneath Acidalia Planitia might be the best place to search for Martian life, existing in the form of methane-belching microbes on Mars. Image via ESA/ DLR/ FU Berlin/ G. Neukum (CC BY-SA 3.0 IGO).
Is there life on Mars? If so, it is likely microbial and deep below the surface, where temperatures are warmer and it is protected from the harsh surface conditions.
The best place to search is beneath a vast plain called Acidalia Planitia, in the northern hemisphere, according to a new study from Spain.
Any microbes there might be methanogens, organisms that expel methane as a byproduct. They might help explain the puzzling mystery of methane in Mars’ atmosphere.
Are there microbes on Mars?
Does life exist anywhere on Mars today? Mars’ surface is extremely cold, with a whisper-thin atmosphere and harsh radiation coming from the sun. But some scientists think living microbes might survive deep below the surface of Mars. And now, researchers in Spain say they’ve identified the best place to search: Acidalia Planitia, a vast plain in Mars’ northern hemisphere. The researchers said that microbes on Mars would most likely be methanogens, which are also found on Earth, and which leave behind methane as a byproduct. It’s a scenario that might help explain the mysterious presence of small amounts of methane in Mars’ atmosphere.
Astrophysicist Paul M. Sutter wrote about the news in Universe Today on December 21, 2024. The researchers submitted their peer-reviewed paper to the journal Astrobiology on November 22, 2024. A preprint version is also available on arXiv.
Andrea Butturini at the University of Barcelona in Spain led the new study. The research team looked for locations on Earth that could be analogs for the Martian environment. These are also places where methanogens exist. Methanogens are anaerobic (requiring an absence of free oxygen, that is, oxygen that is not a part of a compound) archaea that produce methane as a byproduct of their metabolism. The researchers found three kinds of locations that were analogous to Mars. As Sutter wrote in Universe Today:
The researchers found three potential Mars-like conditions on Earth where methanogens make a home. The first is deep in the crust, sometimes to a depth of several kilometers, where tiny cracks in rocks allow for liquid water to seep in. The second is lakes buried under the Antarctic polar ice cap, which maintain their liquid state thanks to the immense pressures of the ice above them. And the last is super-saline, oxygen-deprived basins in the deep ocean.
Earthly analogs where methanogens thrive
Those kinds of conditions also exist on Mars. So, could methanogenic-types microbes live there?
On Earth, the researchers mapped out the analog locations. They measured temperature ranges, salinity (salt) levels and pH values (acidity). In addition, they measured the abundance of molecular hydrogen at those locations. With all the data, the research team determined specifically where methanogens were most abundant.
Then, the data were compared to data from Mars, to find which locations on Mars were the most similar to those on Earth where methanogens thrived. One region in particular stood out: Acidalia Planitia. This is a vast plain in the northern hemisphere of Mars. It is a geologically rich region, with evidence for past hot springs, steam vents, glaciers and even possible mud volcanoes and oceans.
Here, conditions are the most similar to the Earthly analogs. Not on the surface, but rather below it. Several miles deep, in fact.
Acidalia Planitia, by the way, was the landing region for the human mission to Mars in both the book and movie “The Martian.”
This image in the Acidalia Planitia region of Mars shows numerous round hills that have a large circular depression on their tops. These pitted mounds may be ancient mud volcanoes.https://t.co/148A3dTnRJ
NASA/JPL-Caltech/UArizona#Marspic.twitter.com/r9zZMusGw5
— HiRISE: Beautiful Mars (NASA) (@HiRISE) July 19, 2023
Acidalia Planitia, the best place for life on Mars?
The intense debate about the presence of methane in the Martian atmosphere has stimulated the study of methanogens adapted to terrestrial habitats that mimic Martian environments. We examinate the environmental conditions, energy sources and ecology of terrestrial methanogens thriving in deep crystalline fractures, sub-sea hypersaline lakes and subglacial water bodies considered as analogs of a hypothetical habitable Martian subsurface.
We combine this information with recent data on the distribution of buried water or ice and radiogenic elements on Mars and with models of the subsurface thermal regime of this planet to identify a 4.3-8.8 km-deep [2.6-5.4 miles] regolith habitat at the mid-latitude location of Acidalia Planitia, that might fit the requirements for hosting putative Martian methanogens analogous to the methanogenic families Methanosarcinaceae and Methanomicrobiaceae.
The paper concluded:
As a result, both our analysis (which builds upon recent advances in understanding Mars’ subsurface) and previous research more focused on its surface converge in identifying the southern of Acidalia Planitia as a promising target area for future missions in the search for extant life in Mars’ subsurface.
Still a challenging environment
Even though conditions beneath the surface in Acidalia Planitia are far better than on the surface, it would still be a challenging environment for microbial life. As the paper noted:
Methanogens are significant, but not ubiquitous, in the microbial ecosystems thriving in the subsurface ecosystems believed to be terrestrial analogs of the Martian subsurface. Thus, although methanogens feed on simple molecules and their metabolism can be described by straightforward redox equations – making them ideal models for astrobiologists – studies of terrestrial deep temperate-hot crystalline fractures are revealing that these habitats are challenging for methanogens. Consequently, the cold Martian subsurface is likely an even harsher habitat for putative terrestrial-like methanogens.
Beyond the need for water, appropriate environmental conditions, and adequate energetic and carbon resources, the proliferation of methanogens also depends on complex ecological constraints. Indeed, methanogens establish ecological and energetic interactions with organisms with diverse metabolisms, suggesting that the conjecture that they might form mono-specific communities does not fit with what is regularly observed in terrestrial subsurface ecosystems. So, if terrestrial-like methanogens were to thrive in Mars’ subsurface, they would most likely be members of a complex and diverse ecosystem.
View larger. | Scientists have hypothesized several explanations for how methane is created, and then destroyed, in Mars’ atmosphere. Currently, the consensus is that it most likely originates underground. Methanogenic microbes are one of the possibilities. Image via ESA.
The subsurface of the southern of Acidalia Planitia is a putative target region for hosting cold-adapted Methanosarcinaceae-like and/or Methanomicrobiaceae-like methanogens (if they can associate with bacteria-like organisms). In this region, the radiogenic heat-producing elements are at the highest abundance and subsurface water is likely. Thus, water radiolysis could supply the energetic resources required for these hypothetical methanogens.
Our knowledge of Mars’ subsurface is advancing thanks to orbiters, landers and rovers, but critical gaps exist. To make substantial progress in identifying habitable niches in the subsurface of Mars, it will be essential to elucidate the availability of inorganic carbon in the subsurface, and to determine more accurately the depth at which water is located and the porosity/fracturing of the regolith, as these factors directly affect the thermal gradients and the efficiency of water radiolysis.
Needless to say, actually finding any evidence for microbes that far below the Martian surface will be difficult. Even now, rovers can only drill a matter of inches – or a few feet as with the upcoming ExoMars rover – into the ground or rocks. But perhaps another future mission will be able to analyze the puzzling methane emissions even closer, and determine whether they have a biological or non-biological source. That could reveal the existence of the hypothetical methanogens without having to dig at all.
Bottom line: A new study suggests that microbes on Mars might exist deep below the surface, and in one region in particular. They might even explain Martian mysterious methane.
