Have astronomers spotted the collision of two exoplanets around a Sunlike star?

9:36 am

Changes in the infrared

Using data from a number of orbiting space telescopes, astronomers think they have detected the collision of two exoplanets, producing debris that for about 200 days variably blocked the light from the system’s star.

The images to the right come from figure 1 of their published paper [pdf], showing changes in the infrared as detected by the WISE space telescope. From the press release:

The star, named Gaia20ehk, was about 11,000 light-years from Earth near the constellation Pupis. It was a stable “main sequence” star, much like our sun, which meant that it should emit steady, predictable light. Yet this star began to flicker wildly. “The star’s light output was nice and flat, but starting in 2016 it had these three dips in brightness. And then, right around 2021, it went completely bonkers,” said Tzanidakis, a doctoral candidate in astronomy at the University of Washington. “I can’t emphasize enough that stars like our sun don’t do that. So when we saw this one, we were like ‘Hello, what’s going on here?’”

The cause of the flickering had nothing to do with the star itself: Huge quantities of rocks and dust — seemingly from out of nowhere — were passing in front of the distant star as the material orbited the system, patchily dimming the light that reached Earth. The likely source of all that debris was even more remarkable: a catastrophic collision between two planets.

…“The infrared light curve was the complete opposite of the visible light,” Tzanidakis said. “As the visible light began to flicker and dim, the infrared light spiked. Which could mean that the material blocking the star is hot — so hot that it’s glowing in the infrared.”

A cataclysmic collision between planets would certainly produce enough heat to explain the infrared energy. What’s more, the right kind of collision could also explain those initial dips in light.

The data suggests the collision occurred at an orbit comparable to that of the Earth’s, and took more than a half a year to largely dissipate.

All of this is a reasonable hypothesis based on the data available. Though there is a lot of uncertainty in this conclusion, the researchers considered other explanations, such as variability in the star itself, and found them less credible.

1 comment

FCC chairman blasts Amazon and its Leo satellite constellation

9:08 am

FCC logo

Brendan Carr, the chairman of the Federal Communications Commission, yesterday harshly criticized Amazon for filing papers opposing SpaceX’s application to place a million new satellites into orbit while failing to meet its own FCC license requirement to get 1,600 Amazon Leo satellites in orbit by July 2026.

Amazon should focus on the fact that it will fall roughly 1,000 satellites short of meeting its upcoming deployment milestone, rather than spending their time and resources filing petitions against companies that are putting thousands of satellites in orbit.

To put it mildly, Carr’s point is well taken. In legally protesting SpaceX’s proposed constellation while failing to launch on time as promised, Amazon is following what appears to be standard Jeff Bezos’ practice, epitomized by his rocket company Blue Origin. When customers begin favoring others because the Bezos company either submits a poor bid or fails to meet schedules, the Bezos companies routinely go to court in an attempt to squelch that better competition.

Carr is demanding Amazon stop this, and focus instead on getting its own job done for once. Carr is also signaling the FCC’s position on both SpaceX and Amazon. It is likely going to reject Amazon’s filing and give its okay to SpaceX’s million-satellite constellation, in one form or another.

Carr is also telling Amazon that it faces some push back for failing to launch the required number of Amazon Leo satellites on time. Though it is extremely unlikely the FCC will cancel Amazon’s Leo license, the FCC might fine it heavily. Or it could impose new limits on the constellation. Carr is also indicating the FCC will treat future Amazon license applications much more stringently.

7 comments

Genesis cover

On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.

The print edition can be purchased at Amazon or any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.


The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
 

"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News

NASA’s Van Allen Probe A burns up over the Pacific

8:49 am

We didn’t all die! Van Allen Probe A, one of two NASA spacecraft launched in 2012 to study the Van Allen radiation belts that circle the Earth, yesterday burned up harmlessly over the Pacific ocean as expected.

Both Van Allen probes have been defunct since around 2019, when they ran out of fuel. Van Allen Probe B weighed about 1,300 pounds, so some pieces probably reached the ocean. Had it returned over land it did carry the small risk of doing harm.

The orbit of the other probe, Van Allen Probe B, is expected to decay sometime around 2030. Like its twin, it is heavy enough that some parts will survive re-entry. It is therefore a prime target for a demonstration mission proving the technology for removing space junk safely and under control. NASA should put out a request for bids to the many orbital tug companies that now exist to do exactly that, as it is NASA’s responsibility to make sure this spacecraft re-enters the atmosphere safely.

0 comments

Firefly launches its Alpha rocket, almost a year after previous launch failure

9:11 pm

Firefly today successfully launched its Alpha rocket, almost a year after a launch failure in April 2025.

This launch, from Firefly’s launchpad at Vandenberg Space Force Base in California, was the last for this version of Alpha, and was designed as a test flight, both to check out the fixes to correct last year’s failure as well as to prove out some of the technology that will be used on the upgraded Alpha to be used on all future flights.

The 2026 launch race:

30 SpaceX
8 China
3 Rocket Lab
2 Russia
1 ULA
1 Europe (Arianespace)
1 Firefly

SpaceX continues to lead the entire world combined in total launches — as it did in both ’24 and ’25 — and is doing almost twice as many launches as everyone else.

3 comments

Conscious Choice cover

Now available in hardback and paperback as well as ebook!

From the press release: In this ground-breaking new history of early America, historian Robert Zimmerman not only exposes the lie behind The New York Times 1619 Project that falsely claims slavery is central to the history of the United States, he also provides profound lessons about the nature of human societies, lessons important for Americans today as well as for all future settlers on Mars and elsewhere in space.

 
Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space, is a riveting page-turning story that documents how slavery slowly became pervasive in the southern British colonies of North America, colonies founded by a people and culture that not only did not allow slavery but in every way were hostile to the practice.  
Conscious Choice does more however. In telling the tragic history of the Virginia colony and the rise of slavery there, Zimmerman lays out the proper path for creating healthy societies in places like the Moon and Mars.

 

“Zimmerman’s ground-breaking history provides every future generation the basic framework for establishing new societies on other worlds. We would be wise to heed what he says.” —Robert Zubrin, founder of the Mars Society.

 

All editions are available at Amazon, Barnes & Noble, and all book vendors, with the ebook priced at $5.99 before discount. All editions can also be purchased direct from the ebook publisher, ebookit, in which case you don't support the big tech companies and the author gets a bigger cut much sooner.

 

Autographed printed copies are also available at discount directly from the author (hardback $29.95; paperback $14.95; Shipping cost for either: $6.00). Just send an email to zimmerman @ nasw dot org.

Leaving Earth cover

Leaving Earth: Space Stations, Rival Superpowers, and the Quest for Interplanetary Travel, can be purchased as an ebook everywhere for only $3.99 (before discount) at amazon, Barnes & Noble, all ebook vendors, or direct from my ebook publisher, ebookit.

If you buy it from ebookit you don't support the big oppressive tech companies and I get a bigger cut much sooner.

 

Winner of the 2003 Eugene M. Emme Award of the American Astronautical Society.

 
"Leaving Earth is one of the best and certainly the most comprehensive summary of our drive into space that I have ever read. It will be invaluable to future scholars because it will tell them how the next chapter of human history opened." -- Arthur C. Clarke

Iapetus: Saturn’s ying-yang moon

11:55 am

Iapetus as seen by Cassini in 2007
Click for original image.

Cool image time! The image to the right, reduced and sharpened to post here, was taken on September 10, 2007 by the Saturn orbiter Cassini as it made its first close fly-by of the moon Iapetus, from a distance of about 45,000 miles.

Iapetus, about 912 miles in diameter, is one of the strangest objects in the solar system. As it orbits Saturn, its leading hemisphere is very dark, covered with almost pitch black material, while its trailing hemisphere is very bright. This picture captures a bit of both, with the dark leading hemisphere visible along the right edge.

In many places, the dark material–thought to be composed of nitrogen-bearing organic compounds called cyanides, hydrated minerals and other carbonaceous minerals–appears to coat equator-facing slopes and crater floors. The distribution of this material and variations in the color of the bright material across the trailing hemisphere will be crucial clues to understanding the origin of Iapetus’ peculiar bright-dark dual personality.

There are several theories to explain the planet’s strange ying-yang two-tone coloration. One suggests it is material thrown off by other Saturn moons that Iapetus sweeps up. Other theories suggest the planet’s orbit itself causes the two hemispheres to have different temperatures, allowing material to sublimate off the dark side and to the bright side.

No theory is presently accepted. Nor does any explain the data fully.

Tomorrow I’ll post a most intriguing close-up of Iapetus taken by Cassini during that 2007 fly-by.

0 comments

Interstellar comet 3I/Atlas is unusually enriched with windshield wiper fluid

10:45 am

New Hubble image of 3I/Atlas
Comet 3I/Atlas as seen by Hubble
in November 2025. Click for original.

While interstellar comet 3I/Atlas is remarkably like most comets from our own solar system, scientists have now found new evidence that it spalled off unusual amounts of methanol (CH3OH) — material normally used as windshield washer fluid, carburetor fluid, and cooking fuel — when it made its close fly-by of the Sun in the fall of 2025.

You can read the paper here [pdf] . The research also detected large amounts of prussic acid (HCN). As the comet made its closest pass to the Sun, the numbers increased. From the paper’s abstract:

The CH3OH production rate increased sharply from August through October, including an uptick near the inner edge of the H2 O sublimation zone at r H = 2 au. Compared to comets measured to date at radio wavelengths, the derived CH3 OH/HCN ratios in 3I/ATLAS of 124+30 −34 and 79−14 +11 on September 12 and 15, respectively, are among the most enriched values measured in any comet, surpassed only by anomalous solar system comet C/2016 R2 (PanSTARRS).

Though the numbers are high, they aren’t outside the range of what has been found in comets from our own solar system. Instead, this data suggests — as has all data so far — that Comet 3I/Atlas is a normal comet, but unique in its own way, as are all comets and in fact every object in space.

4 comments

Fourteen-year-old NASA satellite about to burn up uncontrolled in the atmosphere

9:27 am

Chicken LIttle rules again.

Chicken Little rules again! After fourteen years, the orbit of one of NASA’s two Van Allen Probe satellites is about to decay, causing the 1,323 pound satellite to burn up uncontrolled in the atmosphere.

As of March 9, 2026, the U.S. Space Force predicted that the roughly 1,323-pound spacecraft will re-enter the atmosphere at approximately 7:45 p.m. EDT on March 10, 2026, with an uncertainty of +/- 24 hours. NASA expects most of the spacecraft to burn up as it travels through the atmosphere, but some components are expected to survive re-entry. The risk of harm coming to anyone on Earth is low — approximately 1 in 4,200.

As today is a very slow news day in space news, a lot of the mainstream press is highlighting this story, with the usual fear-mongering about how it could hit the Earth and cause terrible damage. And while it is certainly true that this satellite appears large enough for some pieces to reach the ground, the chances of those pieces causing any real harm is quite slim. In fact, I think NASA’s estimate of 1 in 4,200 to be far too high.

Mission engineers had initially estimated the orbit would decay in the 2030s, but that estimate was based on a prediction of a weak solar maximum. The Sun however was more active than predicted in the past decade, and that activity caused the Earth’s atmosphere to puff up, which in turn acted to accelerate the satellite’s orbital decay.

This incident once again shows us that there is money to be made in removing defunct satellites from orbit. NASA and ESA have both made it clear each would pay a company to do it. So have some private companies. Some of the orbital tug and robotic servicing companies have here an opportunity they need to grab.

8 comments

A nearby red dwarf star has a solar system of four planets, one in the habitable zone

9:11 am

According to a new analysis of new data, astronomers now think the nearby red dwarf star GJ 887, only about 11 light years away, not only has a solar system of four planets, one of those planets is is a super-Earth orbiting the star in the habitable zone.

From the abstract:

With the Bayesian analysis, we confirmed a four-planet model, including the two previously known planets at periods of 9.2619 ± 0.0005 d and 21.784 ± 0.004 d, as well as two newly confirmed exoplanets: an Earth-mass planet, with a 4.42490 ± 0.00014 d period and a sub-meter-per-second amplitude, and a super-Earth with a 50.77 ± 0.05 d period located in the habitable zone (HZ). This super-Earth is the second closest planet in the HZ, after Proxima Cen b.

The super-Earth has a mass estimated to be anywhere from two to ten times that of Earth, so if any life could exist on it that life would have to be adapted for an extremely strong gravitational field. The star itself appears to be relatively benign for an M dwarf, having a “low level of magnetic activity”, though it does exhibit some flaring that could pose a threat to the development of life on the planet.

Unfortunately, this system is not aligned in a way to allow transits of these planets across the face of the star, so these conclusions are based on gravitational wobbles of the star analyzed by computer modeling. Lots of uncertainty. The scientists hope that direct observations of the planet by future space telescopes will reduce these uncertainties. At the moment, the proposed privately-funded Lazuli optical orbiting telescope has the best chance of doing this work, but it isn’t expected to launch before the end of the decade. It will have a 3.1 meter primary mirror, larger than Hubble’s 2.4 meter mirror.

It is a so far very slow news day in space.

5 comments
1 … 37 38 39 40 41 … 2,927