A 8.8-magnitude earthquake struck 73 miles (118 km) off the coast of Russia’s Far Eastern Kamchatka Peninsula at 10:24 a.m. PETT Wednesday, July 30 (23:24 UTC on Tuesday, July 29). A tsunami of up to 13 feet (4 meters) struck the Russian coast following the quake. Via USGS
A 8.8-magnitude earthquake struck 73 miles (118 km) off the coast of Russia’s Far Eastern Kamchatka Peninsula at 11:24 a.m. PETT Wednesday, July 30 (23:24 UTC on Tuesday, July 29), the USGS said. A tsunami as tall as 13 feet (4 meters) also struck the Russian coast following the quake, the news agency Reuters reported.
The US Tsunami Warning System issued tsunami warnings and advisories for Russia, Japan, Alaska and Hawaii. The Japan Weather Agency also issued a warning. It expected tsunami waves of up to 10 feet (3 meters) to reach large coastal areas in that country starting around 01:00 UTC on Wednesday, July 30. The Associated Press reports a 1-foot (30 cm) tsunami at Nemuro on the eastern coast of Hokkaido, Japan’s second largest island.
Video footage shared via social media appears to show widespread damage on the Russian coastline.
Tsunami advisories have also been issued for the Pacific coast of Canada and the US, as well as in New Zealand. The tsunami appears to be smaller than predicted in Japan, reaching 1 foot (30 cm).
Russian earthquake 8th largest ever recorded
Professor Alice-Agnes Gabriel of the Scripps Institution of Oceanography said the quake could be the largest since 2011 and the 8th largest ever recorded.
Magnitude 8.7 #earthquake in Kamchatka, following a M7.4 last week – may be largest earthquake since 2011, 8th largest on record globally, #tsunami warning in place for US west coast and Canada – the historic 1952 M9 closely caused a destructive tsunami across the Pacific
The earthquake was originally reported by the USGS as magnitude 8.0. However, that number was later updated to magnitude 8.8. It occurred at a depth of 13 miles (20.7 km). The epicenter was located at 52.530°N 160.165°E.
Bottom line: A magnitude-8.8 earthquake struck off the coast of eastern Russia on Wednesday, July 29. The resulting 13-foot (4-meters) tsunami struck the Russian coast.
A 8.8-magnitude earthquake struck 73 miles (118 km) off the coast of Russia’s Far Eastern Kamchatka Peninsula at 10:24 a.m. PETT Wednesday, July 30 (23:24 UTC on Tuesday, July 29). A tsunami of up to 13 feet (4 meters) struck the Russian coast following the quake. Via USGS
A 8.8-magnitude earthquake struck 73 miles (118 km) off the coast of Russia’s Far Eastern Kamchatka Peninsula at 11:24 a.m. PETT Wednesday, July 30 (23:24 UTC on Tuesday, July 29), the USGS said. A tsunami as tall as 13 feet (4 meters) also struck the Russian coast following the quake, the news agency Reuters reported.
The US Tsunami Warning System issued tsunami warnings and advisories for Russia, Japan, Alaska and Hawaii. The Japan Weather Agency also issued a warning. It expected tsunami waves of up to 10 feet (3 meters) to reach large coastal areas in that country starting around 01:00 UTC on Wednesday, July 30. The Associated Press reports a 1-foot (30 cm) tsunami at Nemuro on the eastern coast of Hokkaido, Japan’s second largest island.
Video footage shared via social media appears to show widespread damage on the Russian coastline.
Tsunami advisories have also been issued for the Pacific coast of Canada and the US, as well as in New Zealand. The tsunami appears to be smaller than predicted in Japan, reaching 1 foot (30 cm).
Russian earthquake 8th largest ever recorded
Professor Alice-Agnes Gabriel of the Scripps Institution of Oceanography said the quake could be the largest since 2011 and the 8th largest ever recorded.
Magnitude 8.7 #earthquake in Kamchatka, following a M7.4 last week – may be largest earthquake since 2011, 8th largest on record globally, #tsunami warning in place for US west coast and Canada – the historic 1952 M9 closely caused a destructive tsunami across the Pacific
The earthquake was originally reported by the USGS as magnitude 8.0. However, that number was later updated to magnitude 8.8. It occurred at a depth of 13 miles (20.7 km). The epicenter was located at 52.530°N 160.165°E.
Bottom line: A magnitude-8.8 earthquake struck off the coast of eastern Russia on Wednesday, July 29. The resulting 13-foot (4-meters) tsunami struck the Russian coast.
Hurricane Iona swirling south of the Hawaiian Islands on July 29, 2025, as a major hurricane. Image via CIRA/NOAA.
Hurricane Iona churns south of Hawaii
On the evening of Sunday, July 27, 2025, Tropical Storm Iona became the first named storm of the Central Pacific Ocean’s hurricane season. And 12 hours later – on Monday morning – it became the first hurricane of the season. By Monday night it had already strengthened into a major (category 3) hurricane, with sustained winds of 115 miles per hour. Then, by 5 a.m. Tuesday Hawaiian time (15:00 UTC), Iona had continued to rapidly strengthen, with winds speeds increasing more than 57 miles per hour within 24 hours.
The storm is now a strong category 3 hurricane with sustained winds of 125 miles per hour, according to the National Hurricane Center. Iona is more than 700 miles (1,125 km) south-southeast of Honolulu, Hawaii. And it’s moving to the west, meaning the storm will not directly impact the islands. It is also important to note that even thought Iona is very strong, its overall size is small. The hurricane-force winds of more than 74 miles per hour extend out only 30 miles (50 km) from the center of the eye. Meanwhile, the tropical storm-force winds (winds between 39 and 73 miles per hour) extend 90 miles (145 km) from the center.
While Iona could get a little stronger, it is likely at its peak intensity as it eventually moves into drier air, cooler water temperatures and stronger wind shear. This will not only keeping it from getting stronger, but it will also weaken the hurricane as it moves west.
Tropical Storm Keli
Following Hurricane Iona is the second storm of the season in the Central Pacific, Tropical Storm Keli. Keli is a much smaller and weaker storm, barely holding on to tropical storm strength with sustained winds of 40 miles per hour. Meteorologists don’t expect significant strengthening with Keli, and the storm will likely dissipate by Wednesday, July 30.
Neither tropical cyclone should have much of an impact on Hawaii’s weather. Higher swells and a slight increase in winds are possible, but otherwise the National Weather Service says Iona and Keli should have no real impact on Hawaii.
Tropical Storm Keli to the east (lower right) of Hurricane Iona on Tuesday, July 29, 2025. Image via NOAA/GOES-West.
Maps for Hurricane Iona and Tropical Storm Keli
The forecast cone for Hurricane Iona as of 11 a.m. HST Tuesday, July 29, 2025. Image via National Hurricane Center.The forecast cone for Tropical Storm Keli as of 11 a.m. HST Tuesday, July 29, 2025. Image via National Hurricane Center.
Central Pacific hurricane season
The Central Pacific hurricane season runs from June 1 through November 30, the same timeframe as the Atlantic hurricane season. But that’s where the similarities end. The Atlantic hurricane season on average has 14 named storms, 7 of which become hurricanes, and 3 major hurricanes. In comparison, the Central Pacific hurricane season typically has up to 5 tropical cyclones, which includes tropical depressions, tropical storms and hurricanes. On average, August tends to be the most active month for tropical cyclones in the Central Pacific, with 40% of observed tropical cyclones (in the 1971 through 2013 database.) occurring in this month.
The official forecast for this year’s season calls for up to 4 tropical cyclones from June 1 through November 30. It also calls for a 50% chance of a near-normal season, a 30% chance of below-normal activity, and a 20% chance of the season being more active than normal.
Neither El Niño nor La Niña
Like most tropical forecasts, the seasonal outlook for the Central Pacific can also be tied to the phase of El Niño Southern Oscillation, or ENSO. During an El Niño year, (El Niño is the warm phase of ENSO) the Central Pacific is more likely to see a slightly more active than average season, even later into the year. The latest ENSO update has the current phase as “neutral.” That means it’s neither El Niño nor La Niña, with water temperatures near-normal across the equatorial Pacific Ocean. This likely means the Central Pacific hurricane season will be tied to more localized weather patterns in addition to water temperature, wind shear and presence of dry air.
The season already has two named systems, half of the forecast of four tropical cyclones.
Bottom line: Hurricane Iona and Tropical Storm Keli are the first two tropical cyclones of the Central Pacific hurricane season. But neither should have significant impacts on Hawaii. The forecast for the Central Pacific season is for near normal with up to four tropical cyclones possible.
Hurricane Iona swirling south of the Hawaiian Islands on July 29, 2025, as a major hurricane. Image via CIRA/NOAA.
Hurricane Iona churns south of Hawaii
On the evening of Sunday, July 27, 2025, Tropical Storm Iona became the first named storm of the Central Pacific Ocean’s hurricane season. And 12 hours later – on Monday morning – it became the first hurricane of the season. By Monday night it had already strengthened into a major (category 3) hurricane, with sustained winds of 115 miles per hour. Then, by 5 a.m. Tuesday Hawaiian time (15:00 UTC), Iona had continued to rapidly strengthen, with winds speeds increasing more than 57 miles per hour within 24 hours.
The storm is now a strong category 3 hurricane with sustained winds of 125 miles per hour, according to the National Hurricane Center. Iona is more than 700 miles (1,125 km) south-southeast of Honolulu, Hawaii. And it’s moving to the west, meaning the storm will not directly impact the islands. It is also important to note that even thought Iona is very strong, its overall size is small. The hurricane-force winds of more than 74 miles per hour extend out only 30 miles (50 km) from the center of the eye. Meanwhile, the tropical storm-force winds (winds between 39 and 73 miles per hour) extend 90 miles (145 km) from the center.
While Iona could get a little stronger, it is likely at its peak intensity as it eventually moves into drier air, cooler water temperatures and stronger wind shear. This will not only keeping it from getting stronger, but it will also weaken the hurricane as it moves west.
Tropical Storm Keli
Following Hurricane Iona is the second storm of the season in the Central Pacific, Tropical Storm Keli. Keli is a much smaller and weaker storm, barely holding on to tropical storm strength with sustained winds of 40 miles per hour. Meteorologists don’t expect significant strengthening with Keli, and the storm will likely dissipate by Wednesday, July 30.
Neither tropical cyclone should have much of an impact on Hawaii’s weather. Higher swells and a slight increase in winds are possible, but otherwise the National Weather Service says Iona and Keli should have no real impact on Hawaii.
Tropical Storm Keli to the east (lower right) of Hurricane Iona on Tuesday, July 29, 2025. Image via NOAA/GOES-West.
Maps for Hurricane Iona and Tropical Storm Keli
The forecast cone for Hurricane Iona as of 11 a.m. HST Tuesday, July 29, 2025. Image via National Hurricane Center.The forecast cone for Tropical Storm Keli as of 11 a.m. HST Tuesday, July 29, 2025. Image via National Hurricane Center.
Central Pacific hurricane season
The Central Pacific hurricane season runs from June 1 through November 30, the same timeframe as the Atlantic hurricane season. But that’s where the similarities end. The Atlantic hurricane season on average has 14 named storms, 7 of which become hurricanes, and 3 major hurricanes. In comparison, the Central Pacific hurricane season typically has up to 5 tropical cyclones, which includes tropical depressions, tropical storms and hurricanes. On average, August tends to be the most active month for tropical cyclones in the Central Pacific, with 40% of observed tropical cyclones (in the 1971 through 2013 database.) occurring in this month.
The official forecast for this year’s season calls for up to 4 tropical cyclones from June 1 through November 30. It also calls for a 50% chance of a near-normal season, a 30% chance of below-normal activity, and a 20% chance of the season being more active than normal.
Neither El Niño nor La Niña
Like most tropical forecasts, the seasonal outlook for the Central Pacific can also be tied to the phase of El Niño Southern Oscillation, or ENSO. During an El Niño year, (El Niño is the warm phase of ENSO) the Central Pacific is more likely to see a slightly more active than average season, even later into the year. The latest ENSO update has the current phase as “neutral.” That means it’s neither El Niño nor La Niña, with water temperatures near-normal across the equatorial Pacific Ocean. This likely means the Central Pacific hurricane season will be tied to more localized weather patterns in addition to water temperature, wind shear and presence of dry air.
The season already has two named systems, half of the forecast of four tropical cyclones.
Bottom line: Hurricane Iona and Tropical Storm Keli are the first two tropical cyclones of the Central Pacific hurricane season. But neither should have significant impacts on Hawaii. The forecast for the Central Pacific season is for near normal with up to four tropical cyclones possible.
View larger. | Artist’s concept of TOI 1227 b. The baby exoplanet, about the size of Jupiter, is gradually losing its atmosphere and shrinking in size due to intense X-ray radiation from its red dwarf star. The inset shows the actual star in X-ray light from the Chandra X-ray Observatory. Image via X-ray: NASA/ CXC/ RIT/ A. Varga et al.; Illustration: NASA/ CXC/ SAO/ M. Weiss; Image Processing: NASA/ CXC/ SAO/ N. Wolk.
TOI 1227 b is a young, Jupiter-sized exoplanet 330 light-years away. It orbits close to its small, cool red dwarf star.
NASA’s Chandra X-ray Observatory observed the planet and found that intense radiation from the star is slowly destroying the planet’s deep atmosphere.
TOI 1227 b will completely lose its atmosphere in about a billion years, scientists say. As a result, it will shrink to about 1/10 of its current size.
Meet TOI 1227 b
Planets are born in disks of gas and dust around stars. Then they grow larger as they gradually accumulate material. But NASA’s Chandra X-ray Observatory has found a young gas giant planet that is shrinking, instead. A team of researchers from the U.S., Germany and Australia said on July 16, 2025, that the planet – currently about the size of Jupiter and called TOI 1227 b – is slowly losing its atmosphere. In fact, they estimate its atmosphere will entirely disappear in about a billion years from now. The planet will shrink to about 1/10 of its current size. Why? Because intense X-ray radiation from its host red dwarf star is bombarding this ill-fated world.
The researchers used data from Chandra to measure the amount of X-rays coming from the star. This helps them determine how much the radiation is actually affecting the planet’s atmosphere.
TOI 1227 b is about 330 light-years from Earth. It orbits much closer to its red dwarf star than Mercury orbits our sun. Its orbit is about five times closer to its star than Mercury’s orbit is to the sun. It is also a young planet, at only 8 million years old. That’s still a baby, planetary-wise! The star, TOI 1227, is only 1/10 the mass of the sun and much cooler.
The researchers’ new paper has been accepted for publication in The Astrophysical Journal. A preprint version is available on arXiv, which was submitted on June 4, 2025.
Quick Look: NASA’s Chandra finds baby exoplanet is shrinking. Video via NASA/ CXC/ SAO/ A. Jubett/ YouTube.
Baby exoplanet is now shrinking
TOI 1227 b is still young at 8 million years old; it’s just a baby, basically. Like living things, planets grow after they are first born. This happens as they accumulate gas and dust from the surrounding protoplanetary disk around their stars. As of now, TOI 1227 b is about the size of Jupiter. But it is no longer growing. In fact, it is now shrinking in size. Why?
The planet orbits close to a red dwarf star that emits powerful bursts of X-ray radiation. As often happens, those bursts are pummeling the young planet and gradually stripping away its atmosphere. Consequently, this loss of atmosphere decreases the overall size of TOI 1227 b. As Attila Varga, a Ph.D. student at the Rochester Institute of Technology (RIT) in New York, explained:
It’s almost unfathomable to imagine what is happening to this planet. The planet’s atmosphere simply cannot withstand the high X-ray dose it’s receiving from its star.
Attila Varga, a Ph.D. student at the Rochester Institute of Technology in New York, is the lead author of the new study about TOI 1227 b. Image via LinkedIn.
Sad future for TOI 1227 b
The researchers said TOI 1227 b will likely lose its atmosphere completely, in about a billion years. That means its overall size will diminish greatly, from Jupiter-sized to a small barren rocky world. It will also lose much of its mass, from 17 Earth masses now, to only two Earth masses a billion years from now. The planet is losing the equivalent of Earth’s entire atmosphere about every 200 years. Co-author Alexander Binks at the Eberhard Karls University of Tübingen in Germany said:
The future for this baby planet doesn’t look great. From here, TOI 1227 b may shrink to about 1/10 of its current size and will lose more than 10 percent of its weight.
On a more positive note, however, it’s unlikely that TOI 1227 b has ever hosted any life that would now be facing extinction. Being a gaseous world like Jupiter and so close to its star make the planet most likely uninhabitable, at least for life as we know it.
TOI 1227 b is also the second youngest planet ever to be observed passing in front of – or transiting – its host star. In addition, it has the longest year and the lowest mass of any known exoplanet less than 50 million years old.
Bottom line: NASA’s Chandra X-ray Observatory has found a baby exoplanet that is slowly losing its atmosphere and shrinking as it is pummeled by radiation from its star.
View larger. | Artist’s concept of TOI 1227 b. The baby exoplanet, about the size of Jupiter, is gradually losing its atmosphere and shrinking in size due to intense X-ray radiation from its red dwarf star. The inset shows the actual star in X-ray light from the Chandra X-ray Observatory. Image via X-ray: NASA/ CXC/ RIT/ A. Varga et al.; Illustration: NASA/ CXC/ SAO/ M. Weiss; Image Processing: NASA/ CXC/ SAO/ N. Wolk.
TOI 1227 b is a young, Jupiter-sized exoplanet 330 light-years away. It orbits close to its small, cool red dwarf star.
NASA’s Chandra X-ray Observatory observed the planet and found that intense radiation from the star is slowly destroying the planet’s deep atmosphere.
TOI 1227 b will completely lose its atmosphere in about a billion years, scientists say. As a result, it will shrink to about 1/10 of its current size.
Meet TOI 1227 b
Planets are born in disks of gas and dust around stars. Then they grow larger as they gradually accumulate material. But NASA’s Chandra X-ray Observatory has found a young gas giant planet that is shrinking, instead. A team of researchers from the U.S., Germany and Australia said on July 16, 2025, that the planet – currently about the size of Jupiter and called TOI 1227 b – is slowly losing its atmosphere. In fact, they estimate its atmosphere will entirely disappear in about a billion years from now. The planet will shrink to about 1/10 of its current size. Why? Because intense X-ray radiation from its host red dwarf star is bombarding this ill-fated world.
The researchers used data from Chandra to measure the amount of X-rays coming from the star. This helps them determine how much the radiation is actually affecting the planet’s atmosphere.
TOI 1227 b is about 330 light-years from Earth. It orbits much closer to its red dwarf star than Mercury orbits our sun. Its orbit is about five times closer to its star than Mercury’s orbit is to the sun. It is also a young planet, at only 8 million years old. That’s still a baby, planetary-wise! The star, TOI 1227, is only 1/10 the mass of the sun and much cooler.
The researchers’ new paper has been accepted for publication in The Astrophysical Journal. A preprint version is available on arXiv, which was submitted on June 4, 2025.
Quick Look: NASA’s Chandra finds baby exoplanet is shrinking. Video via NASA/ CXC/ SAO/ A. Jubett/ YouTube.
Baby exoplanet is now shrinking
TOI 1227 b is still young at 8 million years old; it’s just a baby, basically. Like living things, planets grow after they are first born. This happens as they accumulate gas and dust from the surrounding protoplanetary disk around their stars. As of now, TOI 1227 b is about the size of Jupiter. But it is no longer growing. In fact, it is now shrinking in size. Why?
The planet orbits close to a red dwarf star that emits powerful bursts of X-ray radiation. As often happens, those bursts are pummeling the young planet and gradually stripping away its atmosphere. Consequently, this loss of atmosphere decreases the overall size of TOI 1227 b. As Attila Varga, a Ph.D. student at the Rochester Institute of Technology (RIT) in New York, explained:
It’s almost unfathomable to imagine what is happening to this planet. The planet’s atmosphere simply cannot withstand the high X-ray dose it’s receiving from its star.
Attila Varga, a Ph.D. student at the Rochester Institute of Technology in New York, is the lead author of the new study about TOI 1227 b. Image via LinkedIn.
Sad future for TOI 1227 b
The researchers said TOI 1227 b will likely lose its atmosphere completely, in about a billion years. That means its overall size will diminish greatly, from Jupiter-sized to a small barren rocky world. It will also lose much of its mass, from 17 Earth masses now, to only two Earth masses a billion years from now. The planet is losing the equivalent of Earth’s entire atmosphere about every 200 years. Co-author Alexander Binks at the Eberhard Karls University of Tübingen in Germany said:
The future for this baby planet doesn’t look great. From here, TOI 1227 b may shrink to about 1/10 of its current size and will lose more than 10 percent of its weight.
On a more positive note, however, it’s unlikely that TOI 1227 b has ever hosted any life that would now be facing extinction. Being a gaseous world like Jupiter and so close to its star make the planet most likely uninhabitable, at least for life as we know it.
TOI 1227 b is also the second youngest planet ever to be observed passing in front of – or transiting – its host star. In addition, it has the longest year and the lowest mass of any known exoplanet less than 50 million years old.
Bottom line: NASA’s Chandra X-ray Observatory has found a baby exoplanet that is slowly losing its atmosphere and shrinking as it is pummeled by radiation from its star.
Eltanin and Rastaban mark the head of Draco the Dragon. You’ll find these stars in the northern sky.
Some famous pairs of stars
Our human eyes and brains easily pick out pairs of stars on the dome of night, especially if the two stars are relatively bright. On Northern Hemisphere summer nights, a famous pair of stars peers down at us from the northern sky. The two stars are Eltanin and Rastaban. They represent the fiery eyes of the constellation Draco the Dragon.
Like other well-known pairs of stars in our night sky, Eltanin and Rastaban are very noticeable. In that way, they’re like the two stars of the constellation Gemini the Twins, called Castor and Pollux. And they’re like the Little Dipper’s bowl stars Kochab and Pherkad.
Each of these starry pairs is easy to spot. Yet none of the pairs of stars mentioned here are true partners in space. The stars are located at different distances in space and only lie near one another along our line of sight.
View at EarthSky Community Photos. | Prateek Pandey in Bhopal, India, captured this photo of Draco and its stars Eltanin and Rastaban. He wrote: “Midnight rise of the dragon.” Thank you, Prateek!
How to spot Eltanin and Rastaban
Once you become familiar with the brilliant Summer Triangle star pattern – a large asterism consisting of three bright stars in three different constellations – it’s easy to star-hop to the Dragon’s eyes.
Draw an imaginary line from the star Altair through the star Vega to locate nearby Eltanin and Rastaban.
As seen from the mid-northern latitudes, the Dragon’s eyes appear in the northeast sky on spring evenings, nearly overhead on late summer evenings, and in the northwest evening sky in late autumn and early winter.
Science and history of the Dragon’s eyes
Modern astronomy has determined that the star Rastaban lies well over 200 light-years farther away than its counterpart in Draco, Eltanin. Best estimates place Eltanin at 154 light-years and Rastaban at 380 light-years distant.
As seen from Earth, Eltanin appears as the brighter star, but that’s because it’s so much closer to us than Rastaban. If these stars were the same distance away, Rastaban would shine some six times more brightly than Eltanin, and we’d probably no longer think of the two stars as the Dragon’s Eyes. Where they are now, Eltanin is magnitude 2.36 and Rastaban is magnitude 2.79. See if you can discern the difference in brightness between these two stars.
Eltanin looms large in the history of astronomy. James Kaler wrote about Eltaninon his website:
In attempting to find stellar parallax, the annual shift in stellar position caused by the shifting position of the orbiting Earth (from which we get stellar distance), in 1728 James Bradley discovered an aberration of starlight, which is caused by the velocity of the moving Earth relative to the speed of the light coming from the star.
The discovery once and for all proved that Copernicus was right and that the Earth truly does move around the central sun.
The Draconid meteor shower originates from this area every year around October 9. The stars have nothing to do with the meteors. The meteors appear to radiate from this region.
Draco’s identity issues
Normally, with some exceptions, the brightest star in a constellation is called “Alpha” followed by the generative name of the constellation with the second brightest star called “Beta” and the third brightest called “Gamma”, and so on, using letters from the Greek alphabet. Not so with Draco. Eltanin is the Gamma star in its constellation Draco, and yet it is Draco’s brightest star. It outshines Rastaban (Beta Draconis) and also outshines Thuban (Alpha Draconis). Why does Thuban have the Alpha designation in Draco? It’s because Thuban is a former pole star!
This sounds to me like a simple case of identity theft.
The constellation Draco has some identity issues. The Alpha star (Thuban) is its ninth brightest star, the Beta star (Rastaban) is its third brightest star, and the Gamma star (Eltanin) is its second brightest star. And the star Eltanin? For hundreds of years, it answered to the name Rastaben. Wait a minute. Isn’t that the name of the other star in Draco? No, not really. Eltanin was Rastaben, while the other star is Rastaban. That second to the last letter makes all the difference in the world.
Rastaban is derived from the Arabic word meaning the head of the serpent/dragon. Maybe this is where Draco’s identity crisis began: Am I a serpent or a dragon? These things matter. In 1603, Johann Bayer, who assigned these Greek letters to each of the stars in Draco, referred to the star Eltanin as Rastaben.
First, the mathematical wizard Jean Meeus (page 363 of Mathematical Astronomy Morsels V) calls Eltanin the “Queen of the Poles” because this star will be the north pole star in the year 92,020 and then the south pole star in the year 2,083,470! So maybe someday Eltanin will be known as Polaris twice, as pole stars are traditionally named.
Second, Eltanin, now 154 light-years away, is headed toward us. Don’t worry, it will miss us by a cool 28 light-years. But 1,333,000 years from now it will become the brightest star in our sky, and 220,000 years after that it will reach its brightest, at magnitude -1.39. It will remain the brightest star in our nighttime sky for a whopping 700,000 years. By then its name would have been Polaris, then back again to Eltanin, or maybe Rastaben. The International Astronomical Union’s Working Group on Star Names will have something to say about that. Be sure to read updates here at EarthSky.
A zenith star to guide you
Finally, Eltanin is the zenith star. What is a zenith star? The name is used for several things. Zenith Star is a wristwatch, you might be wearing one now. Zenith Star is also a model of a popular telescope, perhaps you have one. And Zenith Star was a military system designed in the 1980s, did you take part in that? If you can check all three boxes, well, that’s just plain weird.
But the zenith star that I’m talking about is a star that passes overhead (the zenith) once a day, or more precisely, every 23 hours, 56 minutes. If the declination of the star matches your latitude on earth, then the star will pass right through your zenith. And Eltanin, at a declination of +51.5 degrees, passes over the heads of the astronomers at Greenwich Observatory in London, England. So it became known as the zenith star. This is important because the Royal Observatory located there keeps track of the time and the prime meridian. And the telescope pointed straight up will pick up this star as it passes overhead each day.
There’s that star again, time to set your watch.
In fact, it is very close to being exactly overhead, only 1/600 of a degree off of true zenith. With precession, that will slowly change over the decades. I doubt they will relocate the observatory to follow it.
What is your zenith star?
So, what is your zenith star? What passes over your head each day? First, find your latitude, then find a star near that declination. How close is close enough? The rules of the zenith star have never been established, so let’s try to find something within one degree of zenith. So, if you live at 35 degrees north latitude, find something between 34 and 36 degrees north.
If you live in Brasilia, Brazil, you have hit the jackpot as your zenith star is the brightest star in the sky: Sirius. Those in Mexico City can claim Arcturus. Portland, Oregon, has Capella. Tokyo gets one of the less bright ones: the star Mirach. And what do Kansas City and Washington, D.C., have in common? Probably nothing, except their zenith star is Vega. Chicago looks straight up to see the Andromeda galaxy. But now we have drifted into zenith galaxies, a topic for another day.
The constellation Draco from Urania’s Mirror by Sidney Hall. Image via Wikimedia Commons.
Bottom line: Eltanin and Rastaban represent the fiery eyes of the constellation Draco the Dragon. Eltanin is also the zenith star for the Greenwich Observatory.
Eltanin and Rastaban mark the head of Draco the Dragon. You’ll find these stars in the northern sky.
Some famous pairs of stars
Our human eyes and brains easily pick out pairs of stars on the dome of night, especially if the two stars are relatively bright. On Northern Hemisphere summer nights, a famous pair of stars peers down at us from the northern sky. The two stars are Eltanin and Rastaban. They represent the fiery eyes of the constellation Draco the Dragon.
Like other well-known pairs of stars in our night sky, Eltanin and Rastaban are very noticeable. In that way, they’re like the two stars of the constellation Gemini the Twins, called Castor and Pollux. And they’re like the Little Dipper’s bowl stars Kochab and Pherkad.
Each of these starry pairs is easy to spot. Yet none of the pairs of stars mentioned here are true partners in space. The stars are located at different distances in space and only lie near one another along our line of sight.
View at EarthSky Community Photos. | Prateek Pandey in Bhopal, India, captured this photo of Draco and its stars Eltanin and Rastaban. He wrote: “Midnight rise of the dragon.” Thank you, Prateek!
How to spot Eltanin and Rastaban
Once you become familiar with the brilliant Summer Triangle star pattern – a large asterism consisting of three bright stars in three different constellations – it’s easy to star-hop to the Dragon’s eyes.
Draw an imaginary line from the star Altair through the star Vega to locate nearby Eltanin and Rastaban.
As seen from the mid-northern latitudes, the Dragon’s eyes appear in the northeast sky on spring evenings, nearly overhead on late summer evenings, and in the northwest evening sky in late autumn and early winter.
Science and history of the Dragon’s eyes
Modern astronomy has determined that the star Rastaban lies well over 200 light-years farther away than its counterpart in Draco, Eltanin. Best estimates place Eltanin at 154 light-years and Rastaban at 380 light-years distant.
As seen from Earth, Eltanin appears as the brighter star, but that’s because it’s so much closer to us than Rastaban. If these stars were the same distance away, Rastaban would shine some six times more brightly than Eltanin, and we’d probably no longer think of the two stars as the Dragon’s Eyes. Where they are now, Eltanin is magnitude 2.36 and Rastaban is magnitude 2.79. See if you can discern the difference in brightness between these two stars.
Eltanin looms large in the history of astronomy. James Kaler wrote about Eltaninon his website:
In attempting to find stellar parallax, the annual shift in stellar position caused by the shifting position of the orbiting Earth (from which we get stellar distance), in 1728 James Bradley discovered an aberration of starlight, which is caused by the velocity of the moving Earth relative to the speed of the light coming from the star.
The discovery once and for all proved that Copernicus was right and that the Earth truly does move around the central sun.
The Draconid meteor shower originates from this area every year around October 9. The stars have nothing to do with the meteors. The meteors appear to radiate from this region.
Draco’s identity issues
Normally, with some exceptions, the brightest star in a constellation is called “Alpha” followed by the generative name of the constellation with the second brightest star called “Beta” and the third brightest called “Gamma”, and so on, using letters from the Greek alphabet. Not so with Draco. Eltanin is the Gamma star in its constellation Draco, and yet it is Draco’s brightest star. It outshines Rastaban (Beta Draconis) and also outshines Thuban (Alpha Draconis). Why does Thuban have the Alpha designation in Draco? It’s because Thuban is a former pole star!
This sounds to me like a simple case of identity theft.
The constellation Draco has some identity issues. The Alpha star (Thuban) is its ninth brightest star, the Beta star (Rastaban) is its third brightest star, and the Gamma star (Eltanin) is its second brightest star. And the star Eltanin? For hundreds of years, it answered to the name Rastaben. Wait a minute. Isn’t that the name of the other star in Draco? No, not really. Eltanin was Rastaben, while the other star is Rastaban. That second to the last letter makes all the difference in the world.
Rastaban is derived from the Arabic word meaning the head of the serpent/dragon. Maybe this is where Draco’s identity crisis began: Am I a serpent or a dragon? These things matter. In 1603, Johann Bayer, who assigned these Greek letters to each of the stars in Draco, referred to the star Eltanin as Rastaben.
First, the mathematical wizard Jean Meeus (page 363 of Mathematical Astronomy Morsels V) calls Eltanin the “Queen of the Poles” because this star will be the north pole star in the year 92,020 and then the south pole star in the year 2,083,470! So maybe someday Eltanin will be known as Polaris twice, as pole stars are traditionally named.
Second, Eltanin, now 154 light-years away, is headed toward us. Don’t worry, it will miss us by a cool 28 light-years. But 1,333,000 years from now it will become the brightest star in our sky, and 220,000 years after that it will reach its brightest, at magnitude -1.39. It will remain the brightest star in our nighttime sky for a whopping 700,000 years. By then its name would have been Polaris, then back again to Eltanin, or maybe Rastaben. The International Astronomical Union’s Working Group on Star Names will have something to say about that. Be sure to read updates here at EarthSky.
A zenith star to guide you
Finally, Eltanin is the zenith star. What is a zenith star? The name is used for several things. Zenith Star is a wristwatch, you might be wearing one now. Zenith Star is also a model of a popular telescope, perhaps you have one. And Zenith Star was a military system designed in the 1980s, did you take part in that? If you can check all three boxes, well, that’s just plain weird.
But the zenith star that I’m talking about is a star that passes overhead (the zenith) once a day, or more precisely, every 23 hours, 56 minutes. If the declination of the star matches your latitude on earth, then the star will pass right through your zenith. And Eltanin, at a declination of +51.5 degrees, passes over the heads of the astronomers at Greenwich Observatory in London, England. So it became known as the zenith star. This is important because the Royal Observatory located there keeps track of the time and the prime meridian. And the telescope pointed straight up will pick up this star as it passes overhead each day.
There’s that star again, time to set your watch.
In fact, it is very close to being exactly overhead, only 1/600 of a degree off of true zenith. With precession, that will slowly change over the decades. I doubt they will relocate the observatory to follow it.
What is your zenith star?
So, what is your zenith star? What passes over your head each day? First, find your latitude, then find a star near that declination. How close is close enough? The rules of the zenith star have never been established, so let’s try to find something within one degree of zenith. So, if you live at 35 degrees north latitude, find something between 34 and 36 degrees north.
If you live in Brasilia, Brazil, you have hit the jackpot as your zenith star is the brightest star in the sky: Sirius. Those in Mexico City can claim Arcturus. Portland, Oregon, has Capella. Tokyo gets one of the less bright ones: the star Mirach. And what do Kansas City and Washington, D.C., have in common? Probably nothing, except their zenith star is Vega. Chicago looks straight up to see the Andromeda galaxy. But now we have drifted into zenith galaxies, a topic for another day.
The constellation Draco from Urania’s Mirror by Sidney Hall. Image via Wikimedia Commons.
Bottom line: Eltanin and Rastaban represent the fiery eyes of the constellation Draco the Dragon. Eltanin is also the zenith star for the Greenwich Observatory.
Corona Borealis, the Northern Crown, with its brightest star Alphecca. Read more about the Northern Crown below. Image via Fred Espenak/ AstroPixels. Used with permission.
On any evening from June, July and August, look for the constellation Corona Borealis, also known as the Northern Crown. However, you’ll need a dark sky to see it. If you have one, the constellation is easy and distinctive. In fact, its stars form a distinct C shape in the night sky. Then, in the middle of the C is a white jewel of a star. This star, the brightest light in the Northern Crown, is called Alphecca or Gemma.
To see this famous C-shaped pattern of stars from the Northern Hemisphere, you’ll be looking high overhead during the evening hours in the northern summer. From the Southern Hemisphere, the constellation is low in the northern sky during the southern winter.
Look for Corona Borealis between 2 bright stars
The Crown is located roughly along a line between two bright stars. The first is the orange star Arcturus in the constellation Boötes the Herdsman. The second is beautiful, blue-white Vega in the constellation Lyra the Harp.
Arcturus has already passed its highest point in the evening at this time of year and is slowly descending to the west. However, Vega is still high in the east in July and overhead in August evenings. With dark skies you’ll notice the orange color of Arcturus and Vega’s bright blue-white tinge.
Corona Borealis is between these two stars, though closer to Vega. Remember, a dark sky is best for seeing this faint semicircle of stars.
Look for Corona Borealis between the bright stars Vega and Arcturus.
Or find it between two constellations
Also, you can look for the Northern Crown between the constellations of Hercules the Strongman and Boötes the Herdsman. See chart below.
The C-shaped – or semicircular – constellation Corona Borealis shines between the constellations Boötes and Hercules. Image via IAU/ Wikipedia/ (CC BY-SA 4.0).
Gem of the Northern Crown
The brightest star in Corona Borealis is Gemma at magnitude 2.21. The meaning of this Latin star name should be obvious. This star is the gem of the Northern Crown. It is 75 light-years distant.
But, as is the case with many stars, this star has more than one name. It’s also called Alphecca. This second name is from an Arabic phrase meaning the bright one of the dish. So you can see that, throughout history, stargazers have identified Corona Borealis with a common shape: a bowl, a disk, or a crown.
By the way, Gemma, aka Alphecca, is an eclipsing binary system. It consists of a smaller sunlike star that passes in front of a brighter star every 17.4 days, as seen from our earthly vantage point.
The second brightest star, Beta Coronae Borealis, has the name of Nusakan. Nusakan shines at magnitude 3.65. Nukasan and Alphecca are a little less than three degrees apart. Nukasan lies 114 light-years away.
The other stars that make up the curved shape of Corona Borealis are all 3rd and 4th magnitude. Theta lies on the other side of Nukasan and Gamma and Delta lie on the other side of Alphecca. Also, Gamma is a double star, but the two are very close and require high magnification and steady skies to see.
Want to see the Blaze Star go nova? X marks the spot! Astronomers said an impending nova will give the constellation of the Northern Crown – Corona Borealis – an additional star that rivals its brightest star. Image via Chris Harvey/ Stellarium. Used with permission.
Watch out for the Blaze Star
The Blaze Star is also in the constellation Corona Borealis. It was supposed to go nova last year. Well, we’re still waiting. But when it finally does erupt, it’ll be a once-in-a-lifetime show in our night sky.
The eagerly awaited Blaze Star nova is a real opportunity for keen night sky observers to witness a “new star” in the sky … but only for a few days before it fades away again.
Corona Borealis, the Northern Crown, with its brightest star Alphecca. Read more about the Northern Crown below. Image via Fred Espenak/ AstroPixels. Used with permission.
On any evening from June, July and August, look for the constellation Corona Borealis, also known as the Northern Crown. However, you’ll need a dark sky to see it. If you have one, the constellation is easy and distinctive. In fact, its stars form a distinct C shape in the night sky. Then, in the middle of the C is a white jewel of a star. This star, the brightest light in the Northern Crown, is called Alphecca or Gemma.
To see this famous C-shaped pattern of stars from the Northern Hemisphere, you’ll be looking high overhead during the evening hours in the northern summer. From the Southern Hemisphere, the constellation is low in the northern sky during the southern winter.
Look for Corona Borealis between 2 bright stars
The Crown is located roughly along a line between two bright stars. The first is the orange star Arcturus in the constellation Boötes the Herdsman. The second is beautiful, blue-white Vega in the constellation Lyra the Harp.
Arcturus has already passed its highest point in the evening at this time of year and is slowly descending to the west. However, Vega is still high in the east in July and overhead in August evenings. With dark skies you’ll notice the orange color of Arcturus and Vega’s bright blue-white tinge.
Corona Borealis is between these two stars, though closer to Vega. Remember, a dark sky is best for seeing this faint semicircle of stars.
Look for Corona Borealis between the bright stars Vega and Arcturus.
Or find it between two constellations
Also, you can look for the Northern Crown between the constellations of Hercules the Strongman and Boötes the Herdsman. See chart below.
The C-shaped – or semicircular – constellation Corona Borealis shines between the constellations Boötes and Hercules. Image via IAU/ Wikipedia/ (CC BY-SA 4.0).
Gem of the Northern Crown
The brightest star in Corona Borealis is Gemma at magnitude 2.21. The meaning of this Latin star name should be obvious. This star is the gem of the Northern Crown. It is 75 light-years distant.
But, as is the case with many stars, this star has more than one name. It’s also called Alphecca. This second name is from an Arabic phrase meaning the bright one of the dish. So you can see that, throughout history, stargazers have identified Corona Borealis with a common shape: a bowl, a disk, or a crown.
By the way, Gemma, aka Alphecca, is an eclipsing binary system. It consists of a smaller sunlike star that passes in front of a brighter star every 17.4 days, as seen from our earthly vantage point.
The second brightest star, Beta Coronae Borealis, has the name of Nusakan. Nusakan shines at magnitude 3.65. Nukasan and Alphecca are a little less than three degrees apart. Nukasan lies 114 light-years away.
The other stars that make up the curved shape of Corona Borealis are all 3rd and 4th magnitude. Theta lies on the other side of Nukasan and Gamma and Delta lie on the other side of Alphecca. Also, Gamma is a double star, but the two are very close and require high magnification and steady skies to see.
Want to see the Blaze Star go nova? X marks the spot! Astronomers said an impending nova will give the constellation of the Northern Crown – Corona Borealis – an additional star that rivals its brightest star. Image via Chris Harvey/ Stellarium. Used with permission.
Watch out for the Blaze Star
The Blaze Star is also in the constellation Corona Borealis. It was supposed to go nova last year. Well, we’re still waiting. But when it finally does erupt, it’ll be a once-in-a-lifetime show in our night sky.
The eagerly awaited Blaze Star nova is a real opportunity for keen night sky observers to witness a “new star” in the sky … but only for a few days before it fades away again.
A new study suggests arachnids originated in the sea, not on land. This discovery comes from a well-preserved fossil that is 500 million years old. Image via Mark Vihtelic/ Unsplash.
Did arachnids originate in the sea?
We’re used to seeing spiders, scorpions and other arachnids hiding in holes or crawling through branches and leaves. But on July 22, 2025, a team of scientists from the United States and the United Kingdom said arachnids likely evolved in the sea. The researchers analyzed an exquisitely preserved fossil of a now-extinct marine creature with an exoskeleton: Mollisonia symmetrica. Arachnids share a similar body structure with this fossil, but the key lies in their unique brain and nervous system.
The researchers published their study in the peer-reviewed journal Current Biology on July 22, 2025.
A challenging theory
Until now, the widely accepted belief has been that arachnids came from a common ancestor that lived on land. From this common ancestor, arachnids began to evolve and diversify. However, a new analysis of a magnificently preserved fossil of a marine animal challenges that idea. The study suggests that arachnids might have begun their evolution in the sea. Before this discovery, the previous fossil record suggested that arachnids lived and diversified exclusively on solid ground.
Marine arthropods such as Mollisonia symmetrica are sea creatures with exoskeletons. Mollisonia symmetrica lived half a billion years ago. Fortunately, a Mollisonia fossil from the Burgess Shale formation of the Canadian Rockies has remained almost intact all this time. It has allowed scientists to perform a detailed analysis of its body structure and the fossilized features of its brain and central nervous system.
Meanwhile, spiders and scorpions have existed for about 400 million years, undergoing relatively few changes. So researchers have been able to make precise comparisons between the fossil and various modern-day arachnids and other animals living on Earth today.
An unexpected discovery
Until now, scientists thought the extinct Mollisonia symmetrica represented an ancestral member of a specific group of arthropods known as chelicerates. These animals lived during the Cambrian Period (between 540 and 485 million years ago) and included the ancestors of today’s horseshoe crabs.
Physically, Mollisonia had a body divided into two parts. First, it had a rounded front carapace, or hard upper shell. And second, it had a segmented trunk ending in a tail-like structure. This body structure resembles that of a scorpion.
In addition, the front part of Mollisonia functioned like the head of a spider: it had organized nerves controlling its limbs. Its small brain also sent signals to a pair of fang-like claws. This structure supports the idea that it was closely related to arachnids.
But what surprised researchers most was discovering that the neural structures in Mollisonia’s fossilized brain were not organized like those of horseshoe crabs, a marine animal. Instead, they mirrored the arrangement found in modern spiders and their relatives.
Arachnids’ brains
Spiders have a distinct brain that sets them apart. Imagine the brains of crustaceans, insects, centipedes and horseshoe crabs, but inverted! That is, the rear part of the brain is in front, and vice versa. According to the lead author of the study and Regents Professor in the Department of Neuroscience at the University of Arizona, Nicholas Strausfeld:
It’s as if the Limulus-type brain [a genus of horseshoe crab] seen in Cambrian fossils, or the brains of ancestral and present days crustaceans and insects, have been flipped backwards, which is what we see in modern spiders.
A side-by-side comparison of the brains of a horseshoe crab (left), the Mollisonia fossil (center) and a modern spider (right). The study found the organization of Mollisonia‘s 3 brain regions (green, magenta and blue) are inverted when compared to the horseshoe crab. Instead, its brain resembles the arrangement found in modern spiders. Image via Nick Strausfeld/ University of Arizona.
How to be sure?
To carry out the study, Strausfeld spent quite some time at Harvard University’s Museum of Comparative Zoology, where the Mollisonia fossil is. There, he took dozens of photographs using different lighting angles, varying intensities, polarized light and magnifications.
The researchers need to rule out the possibility that the similarities between Mollisonia’s brain and that of spiders were due to convergent evolution. As in, that they didn’t evolve similar traits but separately, due to similar environmental situations. So co-author David Andrew – formerly a graduate student in Strausfeld’s lab and now at Lycoming College in Pennsylvania – conducted a statistical analysis. He compared 115 neural and anatomical traits across both extinct and living arthropods.
The results placed Mollisonia as a sister group to modern arachnids. This supports the hypothesis that this ancient creature belongs to the evolutionary lineage that gave rise to today’s spiders, scorpions, solifuges, vinegaroons and other arachnids. According to co-author Frank Hirth from King’s College London:
This is a major step in evolution, which appears to be exclusive to arachnids. Yet already in Mollisonia, we identified brain domains that correspond to living species with which we can predict the underlying genetic makeup that is common to all arthropods.
Unfortunately, other arthropods similar to Mollisonia are not preserved well enough for detailed analysis of their nervous systems. But if they shared the same unique brain structure, their descendants could have formed divergent land-dwelling lineages that now make up various branches of the arachnid tree of life.
Advanced imaging techniques allowed the research team to identify key anatomical features in the fossilized remains of the Mollisonia specimen. Image via Nick Strausfeld/ University of Arizona.
Why an inverted brain?
According to co-author Frank Hirth of King’s College London, this discovery could represent a key step in evolution. Studies on modern spider brains suggest this inverted nervous system organization enables more direct connections between control centers and the circuits that execute movement. And this possibly explains the remarkable agility of spiders and other arachnids.
This design likely gives them stealth in hunting and speed in pursuit. And, in the case of spiders, it gives them refined coordination for spinning webs and capturing prey. Strausfeld explained:
The arachnid brain is unlike any other brain on this planet. And it suggests that its organization has something to do with computational speed and the control of motor actions.
The first creatures to colonize land were probably arthropods similar to millipedes – and possibly some insect ancestors – an evolutionary branch of crustaceans. He added:
We might imagine that a Mollisonia-like arachnid also became adapted to terrestrial life, making early insects and millipedes their daily diet.
Being able to fly gives you a serious advantage when you’re being pursued by a spider. Yet, despite their aerial mobility, insects are still caught in their millions in exquisite silken webs spun by spiders.
Illustration of what Mollisonia would have looked like some 500 million years ago. It likely fed on early insects and millipedes. Image via Nick Strausfeld/ University of Arizona.
Bottom line: We think of spiders, scorpions and other arachnids as land creatures. But according to a new study, they might have originated in the sea.
A new study suggests arachnids originated in the sea, not on land. This discovery comes from a well-preserved fossil that is 500 million years old. Image via Mark Vihtelic/ Unsplash.
Did arachnids originate in the sea?
We’re used to seeing spiders, scorpions and other arachnids hiding in holes or crawling through branches and leaves. But on July 22, 2025, a team of scientists from the United States and the United Kingdom said arachnids likely evolved in the sea. The researchers analyzed an exquisitely preserved fossil of a now-extinct marine creature with an exoskeleton: Mollisonia symmetrica. Arachnids share a similar body structure with this fossil, but the key lies in their unique brain and nervous system.
The researchers published their study in the peer-reviewed journal Current Biology on July 22, 2025.
A challenging theory
Until now, the widely accepted belief has been that arachnids came from a common ancestor that lived on land. From this common ancestor, arachnids began to evolve and diversify. However, a new analysis of a magnificently preserved fossil of a marine animal challenges that idea. The study suggests that arachnids might have begun their evolution in the sea. Before this discovery, the previous fossil record suggested that arachnids lived and diversified exclusively on solid ground.
Marine arthropods such as Mollisonia symmetrica are sea creatures with exoskeletons. Mollisonia symmetrica lived half a billion years ago. Fortunately, a Mollisonia fossil from the Burgess Shale formation of the Canadian Rockies has remained almost intact all this time. It has allowed scientists to perform a detailed analysis of its body structure and the fossilized features of its brain and central nervous system.
Meanwhile, spiders and scorpions have existed for about 400 million years, undergoing relatively few changes. So researchers have been able to make precise comparisons between the fossil and various modern-day arachnids and other animals living on Earth today.
An unexpected discovery
Until now, scientists thought the extinct Mollisonia symmetrica represented an ancestral member of a specific group of arthropods known as chelicerates. These animals lived during the Cambrian Period (between 540 and 485 million years ago) and included the ancestors of today’s horseshoe crabs.
Physically, Mollisonia had a body divided into two parts. First, it had a rounded front carapace, or hard upper shell. And second, it had a segmented trunk ending in a tail-like structure. This body structure resembles that of a scorpion.
In addition, the front part of Mollisonia functioned like the head of a spider: it had organized nerves controlling its limbs. Its small brain also sent signals to a pair of fang-like claws. This structure supports the idea that it was closely related to arachnids.
But what surprised researchers most was discovering that the neural structures in Mollisonia’s fossilized brain were not organized like those of horseshoe crabs, a marine animal. Instead, they mirrored the arrangement found in modern spiders and their relatives.
Arachnids’ brains
Spiders have a distinct brain that sets them apart. Imagine the brains of crustaceans, insects, centipedes and horseshoe crabs, but inverted! That is, the rear part of the brain is in front, and vice versa. According to the lead author of the study and Regents Professor in the Department of Neuroscience at the University of Arizona, Nicholas Strausfeld:
It’s as if the Limulus-type brain [a genus of horseshoe crab] seen in Cambrian fossils, or the brains of ancestral and present days crustaceans and insects, have been flipped backwards, which is what we see in modern spiders.
A side-by-side comparison of the brains of a horseshoe crab (left), the Mollisonia fossil (center) and a modern spider (right). The study found the organization of Mollisonia‘s 3 brain regions (green, magenta and blue) are inverted when compared to the horseshoe crab. Instead, its brain resembles the arrangement found in modern spiders. Image via Nick Strausfeld/ University of Arizona.
How to be sure?
To carry out the study, Strausfeld spent quite some time at Harvard University’s Museum of Comparative Zoology, where the Mollisonia fossil is. There, he took dozens of photographs using different lighting angles, varying intensities, polarized light and magnifications.
The researchers need to rule out the possibility that the similarities between Mollisonia’s brain and that of spiders were due to convergent evolution. As in, that they didn’t evolve similar traits but separately, due to similar environmental situations. So co-author David Andrew – formerly a graduate student in Strausfeld’s lab and now at Lycoming College in Pennsylvania – conducted a statistical analysis. He compared 115 neural and anatomical traits across both extinct and living arthropods.
The results placed Mollisonia as a sister group to modern arachnids. This supports the hypothesis that this ancient creature belongs to the evolutionary lineage that gave rise to today’s spiders, scorpions, solifuges, vinegaroons and other arachnids. According to co-author Frank Hirth from King’s College London:
This is a major step in evolution, which appears to be exclusive to arachnids. Yet already in Mollisonia, we identified brain domains that correspond to living species with which we can predict the underlying genetic makeup that is common to all arthropods.
Unfortunately, other arthropods similar to Mollisonia are not preserved well enough for detailed analysis of their nervous systems. But if they shared the same unique brain structure, their descendants could have formed divergent land-dwelling lineages that now make up various branches of the arachnid tree of life.
Advanced imaging techniques allowed the research team to identify key anatomical features in the fossilized remains of the Mollisonia specimen. Image via Nick Strausfeld/ University of Arizona.
Why an inverted brain?
According to co-author Frank Hirth of King’s College London, this discovery could represent a key step in evolution. Studies on modern spider brains suggest this inverted nervous system organization enables more direct connections between control centers and the circuits that execute movement. And this possibly explains the remarkable agility of spiders and other arachnids.
This design likely gives them stealth in hunting and speed in pursuit. And, in the case of spiders, it gives them refined coordination for spinning webs and capturing prey. Strausfeld explained:
The arachnid brain is unlike any other brain on this planet. And it suggests that its organization has something to do with computational speed and the control of motor actions.
The first creatures to colonize land were probably arthropods similar to millipedes – and possibly some insect ancestors – an evolutionary branch of crustaceans. He added:
We might imagine that a Mollisonia-like arachnid also became adapted to terrestrial life, making early insects and millipedes their daily diet.
Being able to fly gives you a serious advantage when you’re being pursued by a spider. Yet, despite their aerial mobility, insects are still caught in their millions in exquisite silken webs spun by spiders.
Illustration of what Mollisonia would have looked like some 500 million years ago. It likely fed on early insects and millipedes. Image via Nick Strausfeld/ University of Arizona.
Bottom line: We think of spiders, scorpions and other arachnids as land creatures. But according to a new study, they might have originated in the sea.
Comet 3I/ATLAS imaged by the Gemini North telescope. It reveals the comet’s compact coma. That’s the cloud of gas and dust surrounding its icy nucleus. But what if – as some scientists speculate – it’s an alien spacecraft? Image via International Gemini Observatory/ NOIRLab/ NSF/ AURA/K. Meech (IfA/U. Hawaii). Image processing via Jen Miller & Mahdi Zamani (NSF NOIRLab).
To determine whether an object like 3I/ATLAS is artificial, astronomers look for signs such as radio emissions, electrostatic discharges, or intentional course corrections.
Most scientists agree 3I/ATLAS behaves like a normal comet – showing a fuzzy coma and tail – which makes any alien-technology idea unlikely.
And it’s hard to detect interstellar visitors because they’re small, dim, and often only become visible when very close to the sun.
On July 1, astronomers spotted an unusual high-speed object zooming towards the sun. Dubbed 3I/ATLAS, the surprising space traveler had one very special quality: its orbit showed it had come from outside our solar system.
For only the 3rd time ever, we had discovered a true interstellar visitor. And it was weird.
3I/ATLAS breaking records
3I/ATLAS appeared to be traveling at 152,000 miles per hour (245,000 kilometers per hour), making it the fastest object ever detected in our solar system.
Davide Farnocchia, navigation engineer at NASA’s JPL, explains the discovery of 3I/ATLAS.
Could it be alien?
Our first assumption when we see something in space is that it’s a lump of rock or ice. But the strange properties of 3I/ATLAS have suggested to some that it may be something else entirely.
Loeb is a controversial figure among astronomers and astrophysicists. He has previously suggested that the first known interstellar object, 1I/’Oumuamua, discovered in 2017, may also have been an alien craft.
Among other oddities Loeb suggests may be signs of deliberate alien origin, he notes the orbit of 3I/ATLAS takes it improbably close to Venus, Mars and Jupiter.
The trajectory of comet 3I/ATLAS as it passes through the solar system, with its closest approach to the sun in October. NASA/ JPL-Caltech
We’ve sent out our own alien probes
The idea of alien probes wandering the cosmos may sound strange, but humans sent out a few ourselves in the 1970s. Both Voyager 1 and Voyager 2 have officially left our solar system, and Pioneer 10 and 11 are not far behind.
So it’s not a stretch to think that alien civilizations – if they exist – would have launched their own galactic explorers.
However, this brings us to a crucial question: short of little green men popping out to say hello, how would we actually know if 3I/ATLAS, or any other interstellar object, was an alien probe?
Detecting alien probes 101
The first step to determining whether something is a natural object or an alien probe is of course to spot it.
Most things we see in our solar system don’t emit light of their own. Instead, we only see them by the light they reflect from the sun.
Larger objects generally reflect more sunlight, so they are easier for us to see. So what we see tends to be larger comets and asteroid, especially farther from Earth.
It can be very difficult to spot smaller objects. At present, we can track objects down to a size of 32 to 65 feet (10 or 20 meters) out as far from the sun as Jupiter.
Our own Voyager probes are about 32 feet (10 meters) in size (if we include their radio antennas). If an alien probe was similar, we probably wouldn’t spot it until it was somewhere in the asteroid belt between Jupiter and Mars.
If we did spot something suspicious, to figure out if it really were a probe or not we would look for a few telltales.
Viewing 3I/ATLAS through colored filters reveals the colors that make up its tail. International Gemini Observatory/ NOIRLab/ NSF/ AURA/K. Meech (IfA/U. Hawaii)/ Jen Miller and Mahdi Zamani (NSF NOIRLab) (CC BY 4.0).
What would we look for?
First off, because a natural origin is most likely, we would look for evidence that no aliens were involved. One clue in this direction might be if the object were emitting a “tail” of gas in the way that comets do.
However, we might also want to look for hints of alien origin. One very strong piece of evidence would be any kind of radio waves coming from the probe as a form of communication. This is assuming the probe was still in working order, and not completely defunct.
We might also look for signs of electrostatic discharge caused by sunlight hitting the probe.
Another dead giveaway would be signs of maneuvering or propulsion. An active probe might try to correct its course or reposition its antennas to send and receive signals to and from its origin.
And a genuine smoking gun would be an approach to Earth in a stable orbit. Not to brag, but Earth is genuinely the most interesting place in the solar system: we have water, a healthy atmosphere, a strong magnetic field and life. A probe with any decision-making capacity would likely want to investigate and collect data about our interesting little planet.
We may never know
Without clear signs one way or the other, however, it may be impossible to know if some interstellar objects are natural or alien-made.
Objects like 3I/ATLAS remind us that space is vast, strange, and full of surprises. Most of them have natural explanations. But the strangest objects are worth a second look.
For now, 3I/ATLAS is likely just an unusually fast, old and icy visitor from a distant system. But it also serves as a test case: a chance to refine the way we search, observe and ask questions about the universe.
Bottom line: It’s highly unlikely the recently discovered interstellar comet 3I/ATLAS is an alien spacecraft. However, here are things scientists would look for to detect an alien probe.
Comet 3I/ATLAS imaged by the Gemini North telescope. It reveals the comet’s compact coma. That’s the cloud of gas and dust surrounding its icy nucleus. But what if – as some scientists speculate – it’s an alien spacecraft? Image via International Gemini Observatory/ NOIRLab/ NSF/ AURA/K. Meech (IfA/U. Hawaii). Image processing via Jen Miller & Mahdi Zamani (NSF NOIRLab).
To determine whether an object like 3I/ATLAS is artificial, astronomers look for signs such as radio emissions, electrostatic discharges, or intentional course corrections.
Most scientists agree 3I/ATLAS behaves like a normal comet – showing a fuzzy coma and tail – which makes any alien-technology idea unlikely.
And it’s hard to detect interstellar visitors because they’re small, dim, and often only become visible when very close to the sun.
On July 1, astronomers spotted an unusual high-speed object zooming towards the sun. Dubbed 3I/ATLAS, the surprising space traveler had one very special quality: its orbit showed it had come from outside our solar system.
For only the 3rd time ever, we had discovered a true interstellar visitor. And it was weird.
3I/ATLAS breaking records
3I/ATLAS appeared to be traveling at 152,000 miles per hour (245,000 kilometers per hour), making it the fastest object ever detected in our solar system.
Davide Farnocchia, navigation engineer at NASA’s JPL, explains the discovery of 3I/ATLAS.
Could it be alien?
Our first assumption when we see something in space is that it’s a lump of rock or ice. But the strange properties of 3I/ATLAS have suggested to some that it may be something else entirely.
Loeb is a controversial figure among astronomers and astrophysicists. He has previously suggested that the first known interstellar object, 1I/’Oumuamua, discovered in 2017, may also have been an alien craft.
Among other oddities Loeb suggests may be signs of deliberate alien origin, he notes the orbit of 3I/ATLAS takes it improbably close to Venus, Mars and Jupiter.
The trajectory of comet 3I/ATLAS as it passes through the solar system, with its closest approach to the sun in October. NASA/ JPL-Caltech
We’ve sent out our own alien probes
The idea of alien probes wandering the cosmos may sound strange, but humans sent out a few ourselves in the 1970s. Both Voyager 1 and Voyager 2 have officially left our solar system, and Pioneer 10 and 11 are not far behind.
So it’s not a stretch to think that alien civilizations – if they exist – would have launched their own galactic explorers.
However, this brings us to a crucial question: short of little green men popping out to say hello, how would we actually know if 3I/ATLAS, or any other interstellar object, was an alien probe?
Detecting alien probes 101
The first step to determining whether something is a natural object or an alien probe is of course to spot it.
Most things we see in our solar system don’t emit light of their own. Instead, we only see them by the light they reflect from the sun.
Larger objects generally reflect more sunlight, so they are easier for us to see. So what we see tends to be larger comets and asteroid, especially farther from Earth.
It can be very difficult to spot smaller objects. At present, we can track objects down to a size of 32 to 65 feet (10 or 20 meters) out as far from the sun as Jupiter.
Our own Voyager probes are about 32 feet (10 meters) in size (if we include their radio antennas). If an alien probe was similar, we probably wouldn’t spot it until it was somewhere in the asteroid belt between Jupiter and Mars.
If we did spot something suspicious, to figure out if it really were a probe or not we would look for a few telltales.
Viewing 3I/ATLAS through colored filters reveals the colors that make up its tail. International Gemini Observatory/ NOIRLab/ NSF/ AURA/K. Meech (IfA/U. Hawaii)/ Jen Miller and Mahdi Zamani (NSF NOIRLab) (CC BY 4.0).
What would we look for?
First off, because a natural origin is most likely, we would look for evidence that no aliens were involved. One clue in this direction might be if the object were emitting a “tail” of gas in the way that comets do.
However, we might also want to look for hints of alien origin. One very strong piece of evidence would be any kind of radio waves coming from the probe as a form of communication. This is assuming the probe was still in working order, and not completely defunct.
We might also look for signs of electrostatic discharge caused by sunlight hitting the probe.
Another dead giveaway would be signs of maneuvering or propulsion. An active probe might try to correct its course or reposition its antennas to send and receive signals to and from its origin.
And a genuine smoking gun would be an approach to Earth in a stable orbit. Not to brag, but Earth is genuinely the most interesting place in the solar system: we have water, a healthy atmosphere, a strong magnetic field and life. A probe with any decision-making capacity would likely want to investigate and collect data about our interesting little planet.
We may never know
Without clear signs one way or the other, however, it may be impossible to know if some interstellar objects are natural or alien-made.
Objects like 3I/ATLAS remind us that space is vast, strange, and full of surprises. Most of them have natural explanations. But the strangest objects are worth a second look.
For now, 3I/ATLAS is likely just an unusually fast, old and icy visitor from a distant system. But it also serves as a test case: a chance to refine the way we search, observe and ask questions about the universe.
Bottom line: It’s highly unlikely the recently discovered interstellar comet 3I/ATLAS is an alien spacecraft. However, here are things scientists would look for to detect an alien probe.
