Universe Today

January 7, 2025January 7, 2025 by Matt Williams

Here's How Pluto and Charon Became a Bizarre Double Planet

Artist's impression of New Horizons' close encounter with the Pluto–Charon system. Credit: NASA/JHU APL/SwRI/Steve Gribben

On July 14th, 2015, the New Horizons probe made history by accomplishing the first flyby of Pluto and its largest satellite, Charon. The stunning images this mission took of these icy worlds have helped scientists address some of the key questions about Pluto and its massive moon, which have been shrouded in mystery for decades (owing to their great distance from Earth). One of the biggest mysteries that scientists have contemplated since Charon was first discovered in 1978 is how it came together with Pluto in the first place.

For decades, astronomers suspected that Pluto and Charon formed through a process similar to Earth and the Moon. This theory, known as the Giant Impact Hypothesis, states that roughly 4.5 billion years ago, primordial Earth was struck by a Mars-sized body named Theia. In a new study, a team of researchers from the University of Arizona challenged this assumption and offered an alternate theory known as “kiss and capture.” Their findings could help scientists better understand how planetary bodies in the outer Solar System form and evolve.

January 7, 2025January 7, 2025 by Carolyn Collins Petersen

The Lunar Surface Remelted, Obscuring an Easy Answer to its True Age

A few hundred million years after its formation, the Moon was subject to intense volcanic activity. The distance between the Earth and the Moon was much smaller back then than it is today. Lunar surface rocks reflect a younger age due to a "melting" event at the time. MPS / Alexey Chizhik, CC BY-NC-ND

How old is the Moon? Astronaut-gathered samples from the lunar surface put its age at about 4.35 billion years. However, other evidence suggests it’s much older, around 4.53 billion years old. A team of scientists published a recent paper that suggests the Moon’s surface age was “reset” in a melting event.

January 7, 2025January 7, 2025 by Alan Boyle

NASA Lays Out Two New Options for Mars Sample Return

Photomontage of 10 sample capsules sitting on Mars surface — This photomontage shows tubes containing samples from Mars, as collected by NASA’s Perseverance rover. (NASA / JPL-Caltech / MSSS)

Months after deciding that its previous plan for bringing samples back from Mars wasn’t going to work, NASA says it’s working out the details for two new sample return scenarios, with the aim of bringing 30 titanium tubes filled with Martian rocks and soil back to Earth in the 2030s.

One scenario calls for using a beefed-up version of NASA’s sky crane to drop the required hardware onto the Red Planet’s surface, while the other would use heavy-lift commercial capabilities provided by the likes of SpaceX or Blue Origin.

NASA Administrator Bill Nelson said the space agency plans to flesh out the engineering details for each option over the course of the next year and make its choice in 2026. But that all depends on what Congress and President-elect Donald Trump’s administration want to do.

January 7, 2025January 7, 2025 by Andy Tomaswick

A CubeSat Mission Will Detect X-rays from GRBs and Black-Hole Mergers

The long-awaited detection of gravitational waves has opened up a whole new world of astronomy. One of the key efforts is now to tie signals across multiple domains – for example, a gravitational wave and the associated electromagnetic radiation created by that same event, such as a black hole merger or a gamma-ray burst. We’ll need new equipment to detect such “multimodal” signals, especially electromagnetic ones. One such project is the Black Hole Coded Aperture Telescope (BlackCAT), which will be launched early this year by a team led by researchers at Penn State.

January 7, 2025January 7, 2025 by Mark Thompson

Venus is Important. We Should Take its Exploration Seriously.

When it comes to exploring our planetary neighbours, Mars tends to get a lot of the attention. For one thing its easier to explore as the environment is far less hostile than other planets but it also offers the tantalising possibility of finding evidence of primitive life, past or present! Venus however is still a fascinating world and perhaps one that gives us a glimpse into our future if we don’t do something to check global warming. A team of scientists are proposing an official Venus Exploration Program for NASA similar to the existing Mars program.

January 6, 2025January 6, 2025 by Mark Thompson

You’re Made of Carbon that Took a Journey into Intergalactic Space

In this artistic rendering, light from a distant quasar passes through the halo-like circumgalactic medium of a galaxy on its way to Earth, where it is measured by Hubble’s Cosmic Origins Spectrograph to determine the composition of the halo.NASA/ESA/A. Field

I’ve used this fact a gazillion times; every atom in your body has been through the core of a star! The carbon in our bones formed through fusion like many other elements and was thrown out into space to seed the cosmos with the elements for life. A team of researchers have been exploring this journey, tracking a giant conveyor belt that surrounds the Galaxy and the results are surprising.

January 6, 2025January 6, 2025 by Matt Williams

This Superbacteria can Withstand Enough Radiation to Kill a Person

A new study reveals the secret to the antioxidant that allows the bacteria Deinococcus radiodurans to withstand radiation doses 28,000 times greater than what would kill a human. Credit: Northwestern University

Nature is filled with examples of extreme life (aka. extremophiles), which are so-called because they can withstand extreme conditions. These include organisms that can survive in extremely dry conditions, extreme temperatures, acidity, pressure, and even the vacuum of space. The study of these organisms not only helps scientists learn more about the kinds of environments life can survive (and even thrive) in. It also helps astrobiologists to speculate about possible life in the Universe. Perhaps the name “tardigrades” (aka. “water bears”) rings a bell, those little creatures that could survive in interstellar space?

Then you have Deinococcus radiodurans (D. radiodurans), which microbiologists call “Conan the Bacterium” due to its ability to tolerate the harshest conditions. This includes radiation doses thousands of times higher than what would kill a human, or any other organism on Earth, for that matter. In a new study, a team of researchers from Northwestern University and the Uniformed Services University (USU) characterized a synthetic organism inspired by Deinococcus radiodurans that could allow humans to withstand the elevated radiation levels in deep space, on the Moon, and Mars.

January 6, 2025January 6, 2025 by Evan Gough

An Early Supermassive Black Hole Took a Little Break Between Feasts

This artist’s impression shows a black hole about 800 million years after the Big Bang, during one of its short periods of rapid growth. Image Credit: Jiarong Gu

In the last couple of decades, it’s become increasingly clear that massive galaxies like our own Milky Way host supermassive black holes (SMBHs) in their centres. How they became so massive and how they affect their surroundings are active questions in astronomy. Astronomers working with the James Webb Space Telescope have discovered an SMBH in the early Universe that is accreting mass at a very low rate, even though the black hole is extremely massive compared to its host galaxy.

What’s going on with this SMBH, and what does it tell astronomers about the growth of these gargantuan black holes?

January 6, 2025January 6, 2025 by David Dickinson

Will Comet G3 ATLAS Perform at Perihelion?

Comet C/2024 G3 ATLAS may put on a quick show this month.

What ‘may’ be the best anticipated comet of 2025 is coming right up. Right now, there’s only one comet with real potential to reach naked eye visibility in 2025: Comet C/2024 G3 ATLAS. This comet reaches perihelion at 0.094 Astronomical Units (AU, 8.7 million miles or 14 million kilometers, interior to the orbit of Mercury) from the Sun on January 13^th, and ‘may’ top -1^st magnitude or brighter. At magnitude +4 in late December, Comet G3 ATLAS could become a fine object low in the dawn sky for southern hemisphere observers… if (a big ‘if) it holds together and performs as expected.

January 6, 2025January 6, 2025 by Brian Koberlein

A Dragon Reveals Individual Stars From A Time When the Universe Was Half Its Present Age

The galactic cluster Abell 370, with the Dragon Arc highlighted. Credit: NASA, ESA, the Hubble SM4 ERO Team and ST-ECF

One powerful way to study the galaxies is to study individual stars. By looking at the ages, types, and distribution of stars in the Milky Way, we’ve captured a detailed snapshot of how our galaxy formed and evolved. The only problem with this approach is that we can only do this for a handful of galaxies. Even with the most powerful telescopes, we can only see individual stars in the Milky Way and nearby galaxies such as Andromeda. For galaxies billions of light years away, individual stars blur together, and the best we can do is observe the overall spectra of galaxies, not individual stars. But thanks to a chance alignment, we can now observe dozens of stars in a galaxy so distant we see it at a time when the Universe was half its present age.