The JWST Discovers a Galaxy That Shouldn’t Exist

The JWST captured this image of an unusual quiescent dwarf galaxy in the background of separate observations. Image Credit: Carleton et al. 2024

Astronomers working with the JWST found a dwarf galaxy they weren’t looking for. It’s about 98 million years away, has no neighbours, and was in the background of an image of other galaxies. This isolated galaxy shows a lack of star-formation activity, which is very unusual for an isolated dwarf.

Most isolated dwarf galaxies form stars, according to a wealth of observations. What’s different about this one?

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How Could Laser-Driven Lightsails Remain Stable?

Project Starshot, an initiative sponsored by the Breakthrough Foundation, is intended to be humanity's first interstellar voyage. Credit: breakthroughinitiatives.org

It’s a long way to the nearest star, which means conventional rockets won’t get us there. The fuel requirements would make our ship prohibitively heavy. So an alternative is to travel light. Literally. Rather than carrying your fuel with you, simply attach your tiny starship to a large reflective sail, and shine a powerful laser at it. The impulse of photons would push the starship to a fraction of light speed. Riding a beam of light, a lightsail mission could reach Proxima Centauri in a couple of decades. But while the idea is simple, the engineering challenges are significant, because, across decades and light-years, even the smallest problem can be difficult to solve.

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Atmospheres in the TRAPPIST-1 System Should be Long Gone

Illustration of the Trappist-1 system. Credit: NASA/JPL-Caltech

Trappist-1 is a fascinating exoplanetary system. Seven worlds orbiting a red dwarf star just 40 light-years away. All of the worlds are similar to Earth in mass and size, and 3 or 4 of them are potentially habitable. Imagine exploring a system of life-rich worlds within easy traveling distance of each other. It’s a wonderful dream, but as a new study shows it isn’t likely that life exists in the system. It’s more likely the planets are barren and stripped of their atmospheres.

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Astronomers are Getting Really Good at Weighing Baby Supermassive Black Holes

Illustration of an active quasar. New research shows that SMBHs eat rapidly enough to trigger them. Credit: ESO/M. Kornmesser

In the 1970s, astronomers deduced that the persistent radio source coming from the center of our galaxy was actually a supermassive black hole (SMBH). This black hole, known today as Sagittarius A*, is over 4 million solar masses and is detectable by the radiation it emits in multiple wavelengths. Since then, astronomers have found that SMBHs reside at the center of most massive galaxies, some of which are far more massive than our own! Over time, astronomers observed relationships between the properties of galaxies and the mass of their SMBHs, suggesting that the two co-evolve.

Using the GRAVITY+ instrument at the Very Large Telescope Interferometer (VLTI), a team from the Max Planck Institute for Extraterrestrial Physics (MPE) recently measured the mass of an SMBH in SDSS J092034.17+065718.0. At a distance of about 11 billion light-years from our Solar System, this galaxy existed when the Universe was just two billion years old. To their surprise, they found that the SMBH weighs in at a modest 320 million solar masses, which is significantly under-massive compared to the mass of its host galaxy. These findings could revolutionize our understanding of the relationship between galaxies and the black holes residing at their centers.

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Half the Entire Sky, Seen in X-Rays

This image show half of the X-ray sky, projected onto a circle with the center of the Milky Way on the left and the galactic plane running horizontally. Photons have been colour-coded according to their energy (red for energies 0.3-0.6 keV, green for 0.6-1 keV, blue for 1-2.3 keV). Credit: MPE, J. Sanders for the eROSITA consortium
This image show half of the X-ray sky, projected onto a circle with the center of the Milky Way on the left and the galactic plane running horizontally. Photons have been colour-coded according to their energy (red for energies 0.3-0.6 keV, green for 0.6-1 keV, blue for 1-2.3 keV). Credit: MPE, J. Sanders for the eROSITA consortium

There’s an old trope in science fiction about someone suddenly getting X-ray vision and looking through solid objects. It turns out to be a physical impossibility with our Mark I eyeballs. However, astronomers have found a way around that challenge that lets us study the Universe with X-ray vision.

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A Super-Earth (and Possible Earth-Sized) Exoplanet Found in the Habitable Zone

Artist depiction of the surface of a super-Earth orbiting a red dwarf. Credit: ESO/M. Kornmesser

Astronomers have found a new Super-Earth orbiting an M-dwarf (red dwarf) star about 137 light-years away. The planet is named TOI-715b, and it’s about 1.55 Earth’s radius and is inside the star’s habitable zone. There’s also another planetary candidate in the system. It’s Earth-sized, and if it’s confirmed, it will be the smallest habitable zone planet TESS has discovered so far.

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How Dangerous are Kilonovae?

An illustration of the kilonova GW170817. Credit: NASA/CXC/M.Weiss

When we look up at the sky on a particularly dark night, there is a sense of timelessness. We might see the flash of a meteor, and occasionally a comet is visible to the naked eye, but the cold and distant stars are unchanging. Or so it seems. There can also be a sense of calm, that despite all the uncertainty of the world, the stars will always watch over us. So it’s hard to imagine that light years away there could be a lurking event that poses an existential threat to humanity. That threat is extremely tiny, but not zero, and it is the focus of a recent paper published in The Astrophysical Journal.

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An Astronaut Controls a Robotic Dog From Orbit

DLR's four-legged robot Bert explores and monitors the unfamiliar environment. The Surface Avatar Experiment rehearsed an important scenario for future exploration missions on the Moon and Mars. Bert is being developed at the DLR Institute of Robotics and Mechatronics and can walk, trot, gallop, perform a passing gait and even climb. This enables him to cover long distances and at the same time move around in rough terrain or small caves. Credit: DLR.

Swedish astronaut Marcus Wandt took control of a series of robots in Germany while on board the International Space Station, zipping around the Earth at 28,000 kilometers per hour (17,500 mph.) Researchers want to understand how time delays can affect the remote control of robots from an orbiting platform. Future astronauts could control rovers on the Moon’s or Mars’s surface from a spacecraft in orbit. Until now, only wheeled rovers have been part of the tests, but now they have added a dog-like robot called Bert.

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Japan Moon Lander Sleeps After Sending Science — Will It Wake Up Again?

SLIM image of moon
This is the last scene of the moon taken by Japan's SLIM lander before the sun dropped beneath the lunar horizon. (JAXA Photo)

After a few days of wakefulness, Japan’s SLIM moon lander has gone dormant once more at the start of a 14-day-long lunar night. The upended robot sent back a stream of data and imagery while its solar cells were in position to soak up sunlight, and its handlers hope they can get SLIM to wake up again and resume its work after lunar sunrise in mid-February.

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Space Junk is Going to be a Problem for Vera Rubin

The Vera Rubin Observatory is poised to begin observations next year. It could detect 130 Near Earth Objects each night. Image Credit: Rubin Observatory/NSF/AURA/B. Quint

The Vera Rubin Observatory (VRO) is different than other large telescopes, and that difference makes it more vulnerable to space junk. Other telescopes, like the Giant Magellan Telescope and the European Extremely Large Telescope, focus on distant objects. But the VRO’s job is to repeatedly image the entire available night sky for ten years, spotting transients and variable objects.

All that space junk can look like transient events, impairing the VRO’s vision and polluting its results.

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