Universe Today

September 17, 2024September 20, 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.

September 17, 2024September 17, 2024 by Brian Koberlein

Could We Find Primordial Black Holes in the Solar System?

An artistic take on primordial black holes. Credit: NASA’s Goddard Space Flight Center

Astronomers have observed three types of black holes in the Universe. Stellar-mass black holes formed from the collapse of a massive star, intermediate mass black holes found in some star clusters, and supermassive black holes that lurk in the centers of galaxies. But there is a fourth type that remains hypothetical an unobserved. Known as primordial black holes, they are thought to have formed from tiny fluctuations in the hot and dense early cosmos. Since they wouldn’t have formed from stars or mergers, they could have a much smaller mass. And with small masses, primordial black holes would be tiny. Their event horizons would be smaller than an apple, perhaps as small as a grain of sand. You can see why they would be hard to find.

September 17, 2024September 17, 2024 by Mark Thompson

Earth Might Have Had Rings Half a Billion Years Ago

Areas of continental crust proximal to the equator during the Ordovician

Saturn is well known for its ring system and many recognise that the planets Jupiter, Uranus and Neptune also have rings. Did Earth ever have rings though? A team of researchers suggests that a worldwide collection of impact craters points to the existence of a ring around Earth millions of years ago. It’s possible that Earth captured and destroyed an asteroid that passed too close 466 million years ago. The asteroids torn up debris orbited the Earth as a ring and then the individual chunks entered the atmosphere, landed on the surface and produced the craters observed today.

September 17, 2024September 17, 2024 by Mark Thompson

Earth Will Have a Tiny New Mini-Moon for a Few Months

An illustration of a completely unrelated asteroid

The Moon has inspired poets and artists, musicians and playwrights. The sight of our one and only Moon is familiar to anyone that has ever glanced up at the night time (and sometimes day time sky!) Every so often though, our Moon (note the use of capital ‘M’)is joined by a small asteroid that wanders too close. Astronomers have detected an 11-metre wide asteroid that has the snappy name 2024 PT5 and it came within 567,000 kilometres of Earth and will become a temporary satellite from 29 September until 25 November when it will leave our system.

September 16, 2024September 16, 2024 by Evan Gough

A Black Hole has Almost Halted Star Formation in its Galaxy

This is a quiescent galaxy in the early Universe named GS-10578 but nicknamed ‘Pablo’s Galaxy’. It has an SMBH in its center, and astronomers have used the NASA/ESA James Webb Space Telescope to confirm that supermassive black holes can starve their host galaxies of the fuel they need to form new stars. Image Credit: JADES Collaboration

When the James Webb Space Telescope was launched on Christmas Day in 2021, it faced a whole host of intriguing questions. By the time it finally launched, astronomers had a big list of targets begging for the type of detailed observations that only the powerful infrared space telescope could perform. One of the targets was an ancient, massive galaxy that’s basically dead and forms no new stars.

The results are in, and an international team of astronomers know what happened to the quiescent galaxy.

September 16, 2024September 16, 2024 by Andy Tomaswick

An Ambitious Mission to Neptune Could Study Both the Planet and Triton

Mission concepts to the outer solar system are relatively common, as planetary scientists are increasingly frustrated by our lack of knowledge of the farthest planets. Neptune, the farthest known planet, was last visited by Voyager 2 in the 1980s. Technologies have advanced a lot since that probe was launched in 1977. But to utilize that better technology, we first need to have a mission arrive in the system – and one such mission is being developed over a series of papers by ConEx Research and University College London.

September 16, 2024September 17, 2024 by David Dickinson

Earth’s Shadow Nicks the Moon During This Week’s Partial Lunar Eclipse

The Moon just brushes the umbral shadow of the Earth during Tuesday night’s partial lunar eclipse.

A shallow partial lunar eclipse is on tap for the night of September 17th/18th. The eclipse is a slight one to be sure, but will be noticeable as the northwestern limb of the Moon just slips past the dark inner umbral shadow of the Earth. The eclipse is just over 8% partial at its maximum, meaning the Full Moon will look a little ‘smushed’ on one side at mid-eclipse.