Universe Today

September 18, 2024September 18, 2024 by Nancy Atkinson

NASA Watches a Peanut-Shaped Asteroid Drift Past Earth

Near-Earth asteroid 2024 ON. Credit: NASA/JPL.

Peanuts! Get your peanuts here! The Solar System has been passing out peanuts lately in the form of two different oddly shaped asteroids that recently passed by Earth, and both look like over-sized peanuts. The latest peanut-shaped asteroid pass was on September 16, 2024, when the near-Earth asteroid 2024 ON came within 1 million kilometers (62,000 miles) of Earth (2.6 times the Earth-Moon distance). Radar imaging revealed the asteroid was peanut-shaped because it is actually a contact binary – which means it is made of two smaller objects touching each other. NASA says the two rounded lobes are separated by a pronounced neck, and one lobe about 50% larger than the other.

In total, 2024 ON measures about 350 meters (382 yards) long. The radar could resolve features down to about 3.75 meters across on the surface, including brighter boulders. NASA says about 14% of asteroids in this size range (larger than about 200 meters (660 feet)) are contact binaries.

September 18, 2024September 18, 2024 by Mark Thompson

Did Mars Once Have a Third, Larger Moon?

Mars with its two moons Phobos and Deimos

We are all familiar with our one Moon but other planets have different numbers of moons; Mercury has none, Jupiter has 95 and Mars has two. A new paper proposes that Mars may actually have had a third larger moon. Why? The red planet has a triaxial shape which means it bulges just like Earth does but along a third axis. The paper suggests a massive moon could have distorted Mars into this shape.

September 18, 2024September 18, 2024 by Evan Gough

The Early Universe Had a Lot of Black Holes

The Hubble Ultra Deep Field seen in ultraviolet, visible, and infrared light. Image Credit: NASA, ESA, H. Teplitz and M. Rafelski (IPAC/Caltech), A. Koekemoer (STScI), R. Windhorst (Arizona State University), and Z. Levay (STScI)

The Hubble Deep Field and its successor, the Hubble Ultra-Deep Field, showed us how vast our Universe is and how it teems with galaxies of all shapes and sizes. They focused on tiny patches of the sky that appeared to be empty and revealed the presence of countless galaxies. Now, astronomers are using the Hubble Ultra-Deep Field and follow-up images to reveal the presence of a large number of supermassive black holes in the early Universe.

This is a shocking result because, according to theory, these massive objects shouldn’t have been so plentiful billions of years ago.

September 18, 2024September 18, 2024 by Brian Koberlein

SETI Scientists Scan TRAPPIST-1 for Technosignatures

Three of the TRAPPIST-1 planets – TRAPPIST-1e, f and g – dwell in their star’s so-called “habitable zone. CreditL NASA/JPL

If you are going to look for intelligent life beyond Earth, there are few better candidates than the TRAPPIST-1 star system. It isn’t a perfect choice. Red dwarf stars like TRAPPIST-1 are notorious for emitting flares and hard X-rays in their youth, but the system is just 40 light-years away and has seven Earth-sized worlds. Three of them are in the potentially habitable zone of the star. They are clustered closely enough to experience tidal forces and thus be geologically active. If intelligent life arises easily in the cosmos, then there’s a good chance it exists in the TRAPPIST-1 system.

September 18, 2024September 18, 2024 by Evan Gough

A Star Was Kicked Out of a Globular Cluster by an Intermediate-Mass Black Hole

The M15 Globular Cluster (aka. Great Hercules Cluster). Astronomers suspect the existence of one or more intermediate-mass black holes at its heart. Credit: NASA/ESA/HST

Astronomers have solid evidence for the existence of stellar-mass black holes and supermassive black holes. However, evidence for Intermediate Black Holes (IMBHs) is more elusive. Their existence remains hypothetical.

However, study by study, evidence is accumulating for IMBHs. The latest comes from the globular cluster M15, where a fast-moving star suggests the presence of something massive. Could it be an elusive IMBH?

September 17, 2024September 17, 2024 by Matt Williams

Astronomers Have Found a Star with a Hot Jupiter and a Cold Super Jupiter in Orbit

Artist's vision of a cold super-Jupiter in the HD 118203 system. It is an extremely massive gas planet orbiting its star in an orbit six times that of Earth. Credit: NCU/ Maciejewski, G. et al (2024)

Located in the constellation Ursa Major, roughly 300 light-years from Earth, is the Sun-like star HD 118203 (Liesma). In 2006, astronomers detected an exoplanet (HD 118203 b) similar in size and twice as massive as Jupiter that orbits very closely to Liesma (7% of the distance between Earth and the Sun), making it a “Hot Jupiter.” In a recent study, an international team of astronomers announced the detection of a second exoplanet in this system: a Super Jupiter with a wide orbit around its star. In short, they discovered a “Cold Super-Jupiter” in the outskirts of this system.

September 17, 2024September 17, 2024 by Matt Williams

Future Gravitational Wave Observatories Could See the Earliest Black Hole Mergers in the Universe

A simulation of two merging black holes. Credit: Simulating eXtreme Spacetimes (SXS) Project

In February 2016, scientists at the Laser Interferometer Gravitational-wave Observatory (LIGO) confirmed they made the first-ever detection of gravitational waves (GWs). These events occur when massive objects like neutron stars and black holes merge, sending ripples through spacetime that can be detected millions (and even billions) of light-years away. Since the first event, more than 100 GW events have been confirmed by LIGO, the Advanced VIRGO collaboration, and the Kamioka Gravitational Wave Detector (KAGRA).

Moreover, scientists have found numerous applications for GW astronomy, from probing the interiors of supernovae and neutron stars to measuring the expansion rate of the Universe and learning what it looked like one minute after the Big Bang. In a recent study, an international team of astronomers proposed another application for binary black hole (BBH) mergers: using the earliest mergers in the Universe to probe the first generation of stars (Population III) in the Universe. By modeling how the events evolved, they determined what kind of GW signals the proposed Einstein Telescope (ET) could observe in the coming years.

September 17, 2024September 17, 2024 by Andy Tomaswick

Could You Find What A Lunar Crater Is Made Of By Shooting It?

Americans are famously fond of their guns. So it should come as no surprise that a team of NASA scientists has devised a way to “shoot” a modified type of sensor into the soil of an otherworldly body and determine what it is made out of. That is precisely what Sang Choi and Robert Moses from NASA’s Langley Research Center did, though their bullets are miniaturized spectrometers rather than hollow metal casings.

September 17, 2024September 17, 2024 by Evan Gough

There are Plenty of Uses for Powerful Lasers in Space. But Where Should We Put Them?

Recently, Astronomers spotted three near-Earth asteroids (NEAs) hiding in the glare of the Sun. These NEAs are part of an elusive population that lurks inside the orbits of Earth and Venus. One of the asteroids is the largest object that is potentially hazardous to Earth to be discovered in the last eight years. Could we use space lasers to protect Earth from these hazards? Image Credit: DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA/J. da Silva/Spaceengine

Is it time for space lasers yet? Almost.

As time passes, ideas that were once confined to the realm of science fiction become more realistic. It’s true of things like using robots to explore other worlds. Space lasers are a well-used element in science fiction, and we’re approaching the time when they could become a reality.

Where would we put them, and what could we use them for?

September 17, 2024September 17, 2024 by Carolyn Collins Petersen

There Could be a Way to Fix Spacecraft at L2, Like Webb and Gaia

A map of the JWST spacecraft at its SEL2 orbital point in space. Currently there can be no servicing missions to this point, but NASA engineers are studying ways to make them happen. Courtesy NASA's Goddard Space Flight Center

Billions of dollars of observatory spacecraft orbit around Earth or in the same orbit as our planet. When something wears out or goes wrong, it would be good to be able to fix those missions “in situ”. So far, only the Hubble Space Telescope (HST) has enjoyed regular visits for servicing. What if we could work on other telescopes “on orbit”? Such “fixit” missions to other facilities are the subject of a new NASA paper investigating optimal orbits and trajectories for making service calls on telescopes far beyond Earth.