Universe Today

July 31, 2022July 31, 2022 by Brian Koberlein

Planet 9 is Running out of Places to Hide

Illustration of the hypothetical Planet 9. Credit: R. Hurt/IPAC, Caltech

We have a pretty good idea of what lurks within our solar system. We know there isn’t a Mars-sized planet orbiting between Jupiter and Saturn, nor a brown dwarf nemesis heading our way. Anything large and fairly close to the Sun would be easily spotted. But we can’t rule out a smaller, more distant world, such as the hypothetical Planet 9 (or Planet 10 if you want to throw down over Pluto). The odds against such a planet existing are fairly high, and a recent study finds it even less likely.

July 30, 2022July 30, 2022 by Carolyn Collins Petersen

Earth’s Magnetic Field Almost Completely Collapsed 550 Million Years Ago

Visual simulation of the Earth's magnetic field. Credit: NASA Goddard Space Flight Center

More than half a billion years ago, Earth experienced an almost-complete collapse of its magnetic field. It began in the early Cambrian period. Then, after a period of about 15 million years, the field began to grow again. The cause of that collapse and the bounceback of the field was a mystery. Then, a group of geologists studied rocks from Oklahoma that were created during that time. Magnetic markers in the rocks’ minerals pointed toward an event that began some 550 million years ago. That was before the introduction of multicellular life on our planet.

July 30, 2022July 30, 2022 by Nancy Atkinson

China’s Long March Rocket Booster Makes Uncontrolled Reentry Back to Earth

A previous launch of the Long March 5, lifting off from Wenchang on July 2nd, 2017. Credit: CNS

A Chinese Long March 5B rocket first stage made an uncontrolled, fiery reentry through Earth’s atmosphere over Southeast Asia today (Saturday), six days it launched a new science module to China’s Tiangong space station. While the eventual return of the booster was known, China made the decision to let it fall uncontrolled. They also did not share any tracking data, and the large size of the rocket stage drew concern about fragments possibly causing damage or casualties.

The US Space Command confirmed reentry of the debris from the roughly 30-meter-long core (100 ft.) stage of the Long March 5B occurred at 12:45 p.m. Eastern time (1645 UTC) on July 30, 2022 over the Indian Ocean.

July 30, 2022July 30, 2022 by Nancy Atkinson

ESA’s EnVision Mission Doesn’t Have a lot of Fuel, so it’s Going to Aerobrake in the Atmosphere of Venus

Artist impression of ESA's EnVision mission. Credit:ESA/VR2Planets/Damia Bouic

Venus has almost been “the forgotten planet,” with only one space mission going there in the past 30 years. But the recent resurgence of interest in Earth’s closest neighbor has NASA and ESA committing to three new missions to Venus, all due to launch by the early 2030s.

ESA’s EnVision mission Venus is slated to take high-resolution optical, spectral and radar images of the planet’s surface. But to do so, the van-sized spacecraft will need to perform a special maneuver called aerobraking to gradually slow down and lower its orbit through the planet’s hot, thick atmosphere. Aerobraking uses atmospheric drag to slow down a spacecraft and EnVision will make thousands of passages through Venus’ atmosphere for about two years.

July 30, 2022July 30, 2022 by Matt Williams

Jupiter's Giant Moons Prevent it From Having Rings Like Saturn

Saturn and its system of rings, acquired by the Cassini probe. Credit: NASA/JPL-Caltech

When the name Saturn is uttered, what comes to mind? For most people, the answer would probably be, “its fabulous system of rings.” There’s no doubt they are iconic, but what is perhaps lesser-known is that Jupiter, Uranus, and Neptune all have ring systems of their own. However, whereas Saturn’s rings are composed mainly of ice particles (making them highly reflective), Jupiter’s rings are composed mainly of dust grains. Meanwhile, Uranus and Neptune have rings of extremely dark particles known as tholins that are very hard to see. For this reason, none of the other gas giants get much recognition for their rings.

However, the question of why Jupiter doesn’t have larger, more spectacular rings than Saturn has been bothering astronomers for quite some time. As the larger and more massive of the two bodies, Jupiter should have rings that would dwarf Saturn’s by comparison. This mystery may have finally been resolved thanks to new research by a team from UC Riverside. According to their study, Jupiter’s massive moons (aka. Jupiter’s Galilean Moons) prevented it from developing a big, bright, beautiful ring system that would put Saturn’s to shame.

July 30, 2022July 30, 2022 by Brian Koberlein

When Stars eat Their Planets, the Carnage can be Seen Billions of Years Later

Artist view of a large planet soon to be devoured by its star. Credit: NASA, ESA, and G. Bacon (STScI). Science Credit: NASA, ESA, and C. Haswell (The Open University, UK)

The vast majority of stars have planets. We know that from observations of exoplanetary systems. We also know some stars don’t have planets, and perhaps they never had planets. This raises an interesting question. Suppose we see an old star that has no planets. How do we know if ever did? Maybe the star lost its planets during a close approach by another star, or maybe the planets spiraled inward and were consumed like Chronos eating his children. How could we possibly tell? A recent study on the arXiv answers half that question.

July 30, 2022July 30, 2022 by Anton Pozdnyakov

JWST Damage, New Mars Helicopters, Teaching Robots to Die

JWST is doing after its micrometeorite strike, two more helicopters are flying to Mars, China will drop a 50+ meter booster… somewhere, and how do you stop the Milky Way from turning into self-replicating robot probes.

July 29, 2022July 29, 2022 by Scott Alan Johnston

The Mars Sample Return Mission Will Take Two Helicopters to the Red Planet to Help Retrieve Samples

NASA’s upcoming Mars Sample Return mission plan just received a glow-up: it will now carry a pair of twin helicopters, each capable of retrieving samples and delivering them to the ascent vehicle for return to Earth.

July 29, 2022July 30, 2022 by Matt Williams

The James Webb is Measuring Distant Galaxies 5-10 Times Better Than any Other Telescope

Artist conception of the James Webb Space Telescope. Credit: NASA GSFC/CIL/Adriana Manrique Gutierrez

On December 25th, 2021, after many years of waiting, the James Webb Space Telescope (JWST) finally launched to space. In the sixth-month period that followed, this next-generation observatory unfurled its Sunshield, deployed its primary and secondary mirrors, aligned its mirror segments, and flew to its current position at the Earth-Sun Lagrange 2 (L2) Point. On July 12th, 2022, the first images were released and presented the most-detailed views of the Universe. Shortly thereafter, NASA released an image of the most distant galaxy ever observed (which existed just 300 million years after the Big Bang).

According to a new study by an international team of scientists, the JWST will allow astronomers to obtain accurate mass measurements of early galaxies. Using data from James Webb’s Near-Infrared Camera (NIRCam), which was provided through the GLASS-JWST-Early Release Science (GLASS-ERT) program, the team obtained mass estimates from some of the distant galaxies that were many times more accurate than previous measurements. Their findings illustrate how Webb will revolutionize our understanding of how the earliest galaxies in the Universe grew and evolved.

July 28, 2022July 28, 2022 by Matt Williams

A Black Hole can Tear a Neutron Star Apart in Less Than 2 Seconds

Numerical simulation of a black hole-neutron star merger. Credit and ©: K. Hayashi (Kyoto University)

Almost seven years ago (September 14th, 2015), researchers at the Laser Interferometer Gravitational-wave Observatory (LIGO) detected gravitational waves (GWs) for the first time. Their results were shared with the world six months later and earned the discovery team the Noble Prize in Physics the following year. Since then, a total of 90 signals have been observed that were created by binary systems of two black holes, two neutron stars, or one of each. This latter scenario presents some very interesting opportunities for astronomers.

If a merger involves a black hole and neutron star, the event will produce GWs and a serious light display! Using data collected from the three black hole-neutron star mergers we’ve detected so far, a team of astrophysicists from Japan and Germany was able to model the complete process of the collision of a black hole with a neutron star, which included everything from the final orbits of the binary to the merger and post-merger phase. Their results could help inform future surveys that are sensitive enough to study mergers and GW events in much greater detail.