Astronomy Archives

October 5, 2023October 5, 2023 by David Dickinson

It’s Time to Start Worrying About Space Junk Around the Moon, Too

Researchers look to track and mitigate the growing number of space junk objects around the Moon.

It’s getting crowded up there. An increase in military, commercial and scientific launches, coupled with a lower cost for rideshare cubesat launches, means lots more space junk to deal with in coming years. And we’re not just talking about low Earth orbit; the Moon and cis-lunar (near lunar space) is about to become busy as well.

October 4, 2023October 4, 2023 by Evan Gough

Watch OSIRIS-REx Release its Sample Capsule

This is the OSIRIS-Rex sample return capsule in the Great Salt Lake Desert. It's charred and blackened from its plunge through Earth's atmosphere. Image Credit: NASA/Keegan Barber

Most of the spacecraft we send out into the Solar System are never meant to return. Time, space, and entropy overtake them, or else they’re purposely sent crashing to their doom at the end of their missions. But not OSIRIS-REx. Its mission was only a success when it returned to Earth with its rare cargo.

October 4, 2023October 4, 2023 by Evan Gough

Seeing the Web Connecting Galaxies Across the Universe

New research has imaged the Cosmic Web of cold dark gas that interconnects the Universe's galaxies. Image Credit: Martin et al. 2023.

One hundred years ago, we didn’t know there was anything outside of our own galaxy, the Milky Way. Now we know that our puny planet Earth, and everything else, is part of a vast structure called the Cosmic Web. Its scale is difficult to comprehend in any concrete way, and the system’s complexity and magnitude brings our most powerful supercomputers to their knees.

Astronomers have known about the Cosmic Web for some time, as they’ve caught glimpses of it. But a new instrument has given us our most complete view of it yet.

October 3, 2023October 3, 2023 by Matt Williams

Perseverance Watches a Dust Devil Whirl Past

NASA’s Perseverance rover captured this Martian dust devil moving east to west at a clip of about 12 mph (19 kph) along “Thorofare Ridge” on Aug. 30. The video, which was sped up 20 times, is composed of 21 frames taken four seconds apart. It was enhanced in order to show maximal detail. Credit: NASA/JPL-Caltech

On August 30th, 2023, on the 899th Martian day (sol 899) of its mission, NASA’s Perseverance rover spotted a dust devil while exploring the Jezero Crater. The images taken by one of the rover’s Navigation Cameras (NavCams) were used to make a video (shown below), which is composed of 21 frames taken four seconds apart and sped up 20 times. Similar to small, short-lived whirlwinds on Earth, these vertical columns of wind form when pockets of hot air near the surface rise quickly through cooler air above it. By studying them, scientists hope to learn more about Mars’ atmosphere and improve their weather models.

October 3, 2023October 3, 2023 by Evan Gough

Astronomers Have Been Watching a Supernova’s Debris Cloud Expand for Decades with Hubble

This is a Hubble image of a very small region of the Cygnus Loop, a supernova remnant. The image shows a small part of the leading edge of the expanding bubble. Image Credit: NASA, ESA, Ravi Sankrit (STScI)

Twenty thousand years ago, a star in the constellation Cygnus went supernova. Like all supernovae, the explosion released a staggering amount of energy. The explosion sent a powerful shockwave into the surrounding space at half a million miles per hour, and it shows no signs of slowing down.

For twenty years, the Hubble Space Telescope has been watching some of the action.

September 30, 2023September 30, 2023 by Andy Tomaswick

Let the Robot Take the Wheel. Autonomous Navigation in Space

Tracking spacecraft as they traverse deep space isn’t easy. So far, it’s been done manually, with operators of NASA’s Deep Space Network, one of the most capable communication arrays for contacting probes on interplanetary journeys, checking data from each spacecraft to determine where it is in the solar system. As more and more spacecraft start to make those harrowing trips between planets, that system will not be scalable. So engineers and orbital mechanics experts are rushing to solve this problem – and now a team from Politecnico di Milano has developed an effective technique that would be familiar to anyone who has seen an autonomous car.

September 29, 2023October 1, 2023 by Matt Williams

A New Planet-Hunting Instrument Has Been Installed on the Very Large Telescope

ESO VLT — The setting Sun dips below the horizon of the Pacific Ocean, bathing the Paranal platform in light in this amazing aerial image from the Atacama Desert in northern Chile. Credit: ESO

Exoplanet studies have come a long way in a short time! To date, 5,523 exoplanets have been confirmed in 4,117 systems, with another 9,867 candidates awaiting confirmation. With all these planets available for study, exoplanet researchers have been shifting their focus from detection to characterization – i.e., looking for potential signs of life and biological activity (biosignatures). Some major breakthroughs are expected in the coming years, thanks in part to next-generation observatories like NASA’s James Webb and Nancy Grace Roman Space Telescope and the ESA’s PLAnetary Transits and Oscillations of stars (PLATO) mission.

Several ground-based facilities will also be vital to the characterization of exoplanets, like the Extremely Large Telescope (ELT), the Giant Magellan Telescope (GMT), and the Thirty Meter Telescope (TMT). But there are also existing observatories that could be upgraded to perform vital exoplanet research. This idea was explored in a recent paper by an international team of astronomers, who presented the first light results of the High-Resolution Imaging and Spectroscopy of Exoplanets (HiRISE) recently installed on the ESO’s Very Large Telescope (VLT) – not to be confused with the High-Resolution Imaging Science Experiment camera on NASA’s Mars Reconnaissance Orbiter (MRO).

September 29, 2023September 29, 2023 by Evan Gough

Lose Yourself in the JWST’s Exquisite Image of Barnard’s Galaxy

The JWST's NIRCam captured this image of the irregular galaxy NGC 6822. NIRCam probes the near-infrared, which in this case makes it suitable for observing the densely packed star field. Image Credit: ESA/Webb, NASA & CSA, M. Meixner

There may come a day when we grow weary of JWST images. But it’s not today. Today, we can lose ourselves in the space telescope’s engrossing image of NGC 6822, also called Barnard’s Galaxy.

September 28, 2023September 28, 2023 by Matt Williams

If Earth is Average, We Should Find Extraterrestrial Life Within 60 Light-Years

Astronomers have detected thousands of planets, including dozens that are potentially habitable. To winnow them down, they need to understand their atmospheres and other factors. (NASA Illustration)

In 1960, while preparing for the first meeting on the Search for Extraterrestrial Intelligence (SETI), legendary astronomer and SETI pioneer Dr. Frank Drake unveiled his probabilistic equation for estimating the number of possible civilizations in our galaxy – aka. The Drake Equation. A key parameter in this equation was n_e, the number of planets in our galaxy capable of supporting life – aka. “habitable.” At the time, astronomers were not yet certain other stars had systems of planets. But thanks to missions like Kepler, 5523 exoplanets have been confirmed, and another 9,867 await confirmation!

Based on this data, astronomers have produced various estimates for the number of habitable planets in our galaxy – at least 100 billion, according to one estimate! In a recent study, Professor Piero Madau introduced a mathematical framework for calculating the population of habitable planets within 100 parsecs (326 light-years) of our Sun. Assuming Earth and the Solar System are representative of the norm, Madau calculated that this volume of space could contain as much as 11,000 Earth-sized terrestrial (aka. rocky) exoplanets that orbit within their stars’ habitable zones (HZs).

September 25, 2023September 26, 2023 by Matt Williams

Why Build Megastructures? Just Move Planets Around to Make Habitable Worlds

An artist view of countless exoplanets. Credit: NASA/JPL-Caltech

In 1960, Freeman Dyson proposed how advanced civilizations could create megastructures that enclosed their star, allowing them to harness all of their star’s energy and multiplying the habitable space they could occupy. In 2015, the astronomical community was intrigued when the star KIC 8462852 (aka. Tabby’s Star) began experiencing unexplained changes in brightness, leading some to speculate that the variations might be due to a megastructure. While the final analysis of the star’s light curve in 2018 revealed that the dimming pattern was more characteristic of dust than a solid structure, Tabby’s Star focused attention on the subject of megastructures and their associated technosignatures.

Dyson’s ideas were proposed at a time when astronomers were unaware of the abundance of exoplanets in our galaxy. The first confirmed exoplanet was not discovered until 1992, and that number has now reached 5,514! With this in mind, a team of researchers from Bangalore, India, recently released a paper that presents an alternative to the whole megastructure concept. For advanced civilizations looking for more room to expand, taking planets within their system – or capturing free-floating planets (FFP) beyond – and transferring them into the star’s circumsolar habitable zone (HZ) is a much simpler and less destructive solution.