Tag: science

More surprises from the Wolf-Rayet star numbered 104 and known for its pinwheel structure

2:03 pm

Keck infrared data of WR104

Among astronomers who study such things, Wolf-Rayet 104 is one of the most well known OB massive stars in their catalog, with the infrared picture to the right illustrating why. The star is actually a binary of massive stars, orbiting each other every eight months. Both produce strong winds, and the collision of those winds results in a glorious pinwheel structure that glows in the infrared.

Such stars are also believed to be major candidates to go supernova and in doing so produce a powerful gamma ray burst (GRB) that would shoot out from the star’s poles. As the orientation of this pinwheel suggests we are looking down into the pole of the system, this star system was actually considered a potentially minor threat to Earth. Located about 8,400 light years away, this is far enough away to mitigate the power of the GRB, but not eliminate entirely its ability to damage the Earth’s atmosphere.

New research now suggests however that despite the orientation of the pinwheel, face-on, the plane of the binary star system is actually tilted 30 to 40 degrees to our line of sight. The press release asks the new questions these results raise:

While a relief for those worried about a nearby GRB pointed right at us, this represents a real curveball. How can the dust spiral and the orbit be tilted so much to each other? Are there more physics that needs to be considered when modelling the formation of the dust plume?

You can read the paper here. It is a quite refreshing read, not just because of its relatively plain language lacking jargon, but because of its willingness to list at great length the uncertainties of the data.

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Curiosity’s newest view from the heights

10:06 am

Mars in its glorious barrenness
Click for original image.

Overview map
Click for interactive map.

Cool image time! The panorama above, cropped slightly to post here, was taken today by the right navigation camera on the Mars rover Curiosity. It looks north from the rover’s present location on the flank of Mount Sharp, with the rim of Gale Crater in the far distance about 20 to 30 miles away. Curiosity now sits about 3,000 feet above the floor of the crater.

The blue dot on the overview map to the right marks the rover’s position at this time. The yellow lines indicate the approximate view of the panorama. As with all of the images from both Curiosity and Perseverance, the main impression is a barren and lifeless landscape of incredible stark beauty.

It is now very evident that the Curiosity science team has made the decision to abandon their original route to the west. Instead, they have decided to strike south up into this canyon because it provides them the easiest and fastest route to the boxwork geology to the southwest. It also has them climbing into new geological layers rather than descending into layers that the rover has already seen.

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The next time someone tells you Mars lacks water, show them this picture

1:09 pm

Lots of near surface ice on Mars
Click for original image.

In the past decade orbital images from Mars have shown unequivocally that the Red Planet is not the dry desert imagined by sci-fi writers for many decades prior to the space age. Nor is it the dry desert that planetary scientists had first concluded based on the first few decades of planetary missions there.

No, what the orbiters Mars Reconnaissance Orbiter (MRO) and Mars Express have clearly shown is that, except for the planet’s equatorial regions below 30 degrees latitude, the Martian surface is almost entirely covered by water ice, though it is almost always buried by a thin layer of protective dust and debris. Getting to that ice will be somewhat trivial, however, as it is almost always near the surface.

The picture to the right, rotated, cropped, reduced, and sharpened to post here, is a perfect example. It was taken on January 31, 2025 by the high resolution camera on MRO. At the top it shows part of a small glacial-filled crater surrounded by blobby ground clearly impregnated with ice. That crater in turn sits on the rim of a much larger very-eroded ancient 53-mile-wide crater whose floor, also filled with glacial debris, can be seen at the bottom of this picture. The wavy ridge line at the base of the rim appears to be a moraine formed by the ebb and flow of the glacial ice that fills this larger crater.

None of these glacial features is particularly unique on Mars. I have been documenting their presence now at Behind the Black for more than six years. Yet, I find still that most news organizations — including many in the space community — remain utterly unaware of these revelations. Any new NASA or university press release that mentions the near-surface ice that covers about two-thirds of the planet’s surface results in news stories claiming “Water has been found on Mars!”, as if this is a shocking new fact from a place where little water is found.

It is very shameful that so many reporters and news organizations are so far out of touch with the actual state of the research on Mars.
» Read more

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Webb captures infrared images of five exoplanets orbiting two different stars

10:17 am

Four gas giants in infrared
Click for original image.

Using the Webb Space Telescope, astronomers have taken two different direct false-color infrared images of exoplanets orbiting the stars HR 8799 (130 light years away) and 51 Eridani (97 light years away.

The image of the four gas giants orbiting HR 8799 is to the right, cropped, reduced, and slightly enhanced to post here. From the caption:

The closest planet to the star, HR 8799 e, orbits 1.5 billion miles from its star, which in our solar system would be located between the orbit of Saturn and Neptune. The furthest, HR 8799 b, orbits around 6.3 billion miles from the star, more than twice Neptune’s orbital distance. Colors are applied to filters from Webb’s NIRCam (Near-Infrared Camera), revealing their intrinsic differences. A star symbol marks the location of the host star HR 8799, whose light has been blocked by the coronagraph. In this image, the color blue is assigned to 4.1 micron light, green to 4.3 micron light, and red to the 4.6 micron light.

The Webb false color infrared picture taken of one of the exoplanets orbiting the star 51 Eridani is also at the link, showing “a cool, young exoplanet that orbits 890 million miles from its star, similar to Saturn’s orbit in our solar system.”

The data from the HR 8799 image suggests these gas giants have a lot of carbon dioxide gas, and thus might be growing by pulling in material from the star’s accretion disk.

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Scientists issue new map of land below Antarctica’s icecap

1:18 pm

Map of Antarctica's estimated land mass
Click for original image.

Using decades of data and more advanced computer software, scientists have now compiled the most detailed map of the land and shorelines hidden below Antarctica’s massive icecap.

The map to the right, reduced to post here, shows that bedrock terrain generally in hues of green to brown, with lower elevations comparable to the ocean in hues of blue. The actual shoreline is however impossible to determine, since without the pressure of the icecap on top, the continent would rise, while the ocean itself would also rise with the addition of all that water.

You can read the science paper here.. From the press release:

Known as Bedmap3, it incorporates more than six decades of survey data acquired by planes, satellites, ships and even dog-drawn sleds. … The map gives us a clear view of the white continent as if its 27 million cubic km of ice have been removed, revealing the hidden locations of the tallest mountains and the deepest canyons.

One notable revision to the map is the place understood to have the thickest overlying ice. Earlier surveys put this in the Astrolabe Basin, in Adélie Land. However, data reinterpretation reveals it is in an unnamed canyon at 76.052°S, 118.378°E in Wilkes Land. The ice here is 4,757 m thick, or more than 15 times the height of the Shard, the UK’s tallest skyscraper.

The paper describes at length the large uncertainties that exist in this data. As thorough as they tried to be, we must remember that Antarctica is very large with a very hostile environment. Much of it has never been visited by any humans. Getting an accurate picture of the thickness of the ice at all points is presently impossible. This is basically an excellent summary of our best guess.

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Europe’s Hera asteroid probe sends back data from Mars fly-by

1:00 pm

Deimos and Mars as seen by Hera
Click to see full movie.

The European Space Agency (ESA) Hera probe, on its way to study the Didymos/Dimorphos asteroid binary, has successfully sent back images and data obtained during its close-by of Mars yesterday.

The infrared image to the right, a screen capture from a short movie assembled from Hera’s first images, shows the Martian moon Deimos with Mars in the background. The mission scientists have compiled all of these first images taken by Hera to create a short movie, that I have embedded below. From the movie’s caption:

The car-sized Hera spacecraft was about 1000 km away from Deimos as these images were acquired. Deimos orbits approximately 23 500 km from the surface of Mars and is tidally locked, so that this side of the moon is rarely seen. Hera’s TIRI – supplied to the mission by the Japan Aerospace Exploration Agency, JAXA – sees in mid-infrared spectral bands to chart surface temperature. Because Deimos lacks an atmosphere, the side of the moon being illuminated by the Sun is considerably warmer than the planet beneath it.

Although it appears as if Deimos is passing in front of Mars from south to north, the image was actually taken as Hera passed very close to Deimos from north to south at high speed.

Deimos appears brighter than Mars. This means that the surface of airless Deimos is hotter than the surface of Mars. The material covering the surface of Deimos has low reflectivity and is pitch black. This allows it to absorb sunlight well and become hotter. In contrast, the surface of Mars is highly reflective, and its atmosphere transports heat from the warm daytime side to the cooler nighttime side. This is why there is a large temperature difference between Mars and Deimos.

These infrared images also tell us the excellent quality of the camera. Note how detailed the features are on the Martian surface. When Hera gets to Didymos/Dimorphos in December 2026 it is going to be able to document those two asteroids in remarkable detail, including the results of the Dart impact on Dimorphos in September 2022.
» Read more

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Blue Ghost watches the Earth eclipse the Sun from the Moon

10:23 am

Eclipse as seen by Blue Ghost
Click for original image.

Firefly’s Blue Ghost lunar lander last night successfully recorded images and data as the Earth slowly over hours crossed the face of the Sun, producing an eclipse.

The image to the right, cropped and reduced slightly to post here, is one such image. From the Firefly update page:

Captured at our landing site in the Moon’s Mare Crisium around 3:30 am CDT, the photo shows the sun about to emerge from totality behind Earth. This marks the first time in history a commercial company was actively operating on the Moon and able to observe a total solar eclipse where the Earth blocks the sun and casts a shadow on the lunar surface. This phenomenon occurred simultaneously as the lunar eclipse we witnessed on Earth.

The company has the right to tout its success, since it is the first of five private companies to actually succeed at a landing on the Moon. However, this is not the first such eclipse captured by a lander on the Moon. Surveyor 3 did it in April 1967, while Japan’s Kaguya orbiter did it also in 2009. (Watch this great lecture outlining the entire Surveyor program, presented during the 50th anniversary of its success. Hat tip reader Richard M.)

It is now past noon on the Moon, the temperatures will begin dropping, and Firefly will begin reactivating some instruments for the final week of operations before lunar sunset and shutdown for the long very cold lunar night.

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NASA releases Blue Ghost movie landing while Firefly prepares lander to observe solar eclipse of the Moon by Earth

8:54 am

NASA today released a fantastic movie of Firefly’s Blue Ghost lunar lander as it touched down on the Moon on March 2, 2025, taken by four cameras mounted on the underside of its Blue Ghost lunar lander.

I have embedded the movie below.

The compressed, resolution-limited video features a preliminary sequence that NASA researchers stitched together from SCALPSS 1.1’s four short-focal-length cameras, which were capturing photos at 8 frames per second during the descent and landing.

The sequence, using approximate altitude data, begins roughly 91 feet (28 meters) above the surface. The descent images show evidence that the onset of the interaction between Blue Ghost’s reaction control thruster plumes and the surface begins at roughly 49 feet (15 meters). As the descent continues, the interaction becomes increasingly complex, with the plumes vigorously kicking up the lunar dust, soil and rocks — collectively known as regolith. After touchdown, the thrusters shut off and the dust settles. The lander levels a bit and the lunar terrain beneath and immediately around it becomes visible.

Engineers will use this imagery to better anticipate and possibly reduce the amount of dust kicked up during future landings.

Meanwhile, Firefly engineers are preparing the lander to observe tomorrow night’s lunar eclipse, but from a completely different perspective. On Earth we will see the Earth’s shadow slowly over five hours cross the Moon. On the Moon Blue Ghost will see the Earth cross in front of the Sun. Because of our home world’s thick atmosphere, there should be a ring remaining during totality.

Because the Moon will be in shadow during the eclipse, the challenge will be power management, operating the spacecraft solely on its batteries.
» Read more

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Graceful isolated dunes at the edge of the sea of dunes that surrounds Mars’ north ice cap

12:44 pm

Graceful isolated dunes on the edge of the dune sea that surrounds Mars' north pole
Click for original image.

Cool image time! The picture to the right cropped, reduced, and sharpened to post here, was taken on January 29, 2025 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). I have also rotated it so north is up. Labeled simply as a “terrain sample,” it was likely taken not as part of any specific research request but to fill a gap in the schedule in order to maintain the camera’s proper temperature.

In this case the timing allowed the camera team to capture this breath-taking picture of these graceful arching dunes sitting in what is likely the near-surface ice sheet that covers much of the red planet’s high latitudes. That sheet is not pure ice, but a complex mixture of ice, dirt, dust, and sand, covered during the winter by a thin mantle of dry ice.

The isolated dunes appear to be ridges sticking up from that flat terrain, but this impression is probably incorrect, based on the location.
» Read more

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Astronomers discover 128 more moons around Saturn

9:01 am

Using a ground-based telescope, astronomers have now identified 128 new moons circling Saturn, bringing its moon count to 274, more than the total moons around all the other planets in the solar system combined.

Edward Ashton at Academia Sinica in Taipei, Taiwan, and his colleagues found the new moons with the Canada-France-Hawaii Telescope, revealing dozens that have previously evaded astronomers. They took hours of images of Saturn, adjusted them for the planet’s movement through the sky and stacked them on top of each other to reveal objects that would otherwise be too dim to see.

All the new moons are between 2 and 4 kilometres in diameter and are likely to have been formed hundreds of millions or even billions of years ago in collisions between larger moons, says Ashton.

That Saturn has so many moons should surprise no one. Saturn actually has possibly millions, maybe even billions, of moons, if you count every particle in its rings. In fact, the gas giant poses a problem for astronomers in defining what a moon actually is. How small must an object be before you stop calling it a moon?

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SpaceX launches NASA space telescope plus four solar satellites; China launches 18 communication satellites

8:43 am

Two launches to report: First, China yesterday successfully completed its first Long March 8 launch from its new launchpad at its coastal Wenchang spaceport, placing 18 satellites for SpaceSail internet constellation, the fifth group so far launched.

China’s state run press noted that the launchpad is designed to allow the Long March 8 rocket to launch every seven days, a pace needed to place these giant Chinese satellite constellations into orbit.

Next, in the early morning hours today SpaceX successfully launched two different NASA science missions, its Falcon 9 rocket lifting off from Vandenberg in California.

The prime payload was SPHEREx, a space telescope designed to make an all-sky survey. The secondary payload was PUNCH, four satellites forming a constellation to study the Sun.

The rocket’s first stage completed its third flight, landing back at Vandenberg.

The leaders in the 2025 launch race:

27 SpaceX
11 China
3 Russia
2 Rocket Lab

As happened last year, SpaceX handily leads the rest of the world, including American companies, in total launches, 27 to 20. This lead will be extended tonight should the company’s next manned Dragon launch to ISS go off as planned.

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Athena located from lunar orbit

3:12 pm

Athena on the Moon
Click for original master image.

Using Lunar Reconnaissance Orbiter (LRO), scientists have now located and photographed Intuitive Machines lunar lander Athena where it sits on its side on the Moon.

The picture to the right, reduced to post here, shows that location with the small arrow. This is definitely on Mons Mouton, the intended landing zone about 100 miles from the Moon’s south pole. However at the best magnification provided by the LRO science team, the rover is not visible. Reader James Fincannon was puzzled by this and downloaded the highest resolution version of this image and sent it to me. I have added it to the picture as the inset. Athena is the little white dot in the center of a small 65-foot-wide crater. Note that its shadow falls in the opposite direction of all the shadows in the craters, as the lander projects upward from the surface while the craters descend downward.

One can’t help questioning the quality of the lander’s landing software, if it ended up picking the center of this small crater to touch down, especially considering there appear to be large relatively clear flat areas all around.

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