Universe Today

September 8, 2023September 12, 2023 by Nancy Atkinson

DART Had a Surprising Impact on its Target

This Hubble image shows debris from Dimorphos about one day after NASA's DART spacecraft slammed into it. Image Credit: NASA, ESA, STScI, J. Li (PSI)

After NASA’s DART mission slammed into asteroid Dimorphous in September 2022, scientists determined the impact caused tons of rock to be ejected from the small asteroid’s surface. But more importantly, DART’s impact altered Dimorphos’ orbital period, decreasing it by about 33 minutes.

However, a group of researchers measured the orbital period about a month later and discovered that it had increased to 34 minutes — 1 minute longer than the first measurements. Even though it was a single impact from DART, some force continued to slow the asteroid’s orbit, and astronomers don’t yet know what that mechanism might be.

September 8, 2023September 8, 2023 by David Dickinson

Follow the Fall 2023 Return of Comet 103P Hartley

Comet Hartley — Comet 103/P Hartley encounters the Perseus Double Cluster in 2010. Image credit: Kevin Jung

Catch periodic cosmic interloper 103P Hartley while you can.

Periodic comets are like old friends, back for a visit. We have a get together with just such a denizen of the cometary league, as Comet 103P Hartley makes a favorable apparition in late 2023.

September 7, 2023September 7, 2023 by Carolyn Collins Petersen

Mars Doesn’t Have as Many Minerals as Earth

Even though Mars and Earth had similar early histories, including water, Mars still ended up with fewer minerals than Earth. Why? Image Credit: ESO/M. Kornmesser

Earth and Mars are very much alike, but also very different. Among other things, scientists find that Earth is much more mineral-rich than the Red Planet. It has 6,000 different minerals. By contrast, Mars has only 161. That’s a big difference. How could this have happened?

September 7, 2023September 7, 2023 by Jon Voisey

Did a Comet Airburst Destroy a Native American Community?

Artist impression of the Tunguska event.

In 1908, when an object entered the Earth’s atmosphere above the Podkamennaya Tunguska River, it flattened 80 million trees over nearly 2,200 square kilometers, and sent atmospheric shock waves reverberating around the world. Fortunately, this event was in a remote region and very few people were believed to be killed.

But research published in Nature’s Scientific Reports in 2022 by Tankersly et al. suggested that a similar, but even more powerful comet airburst in the Ohio River Valley may have been the death knell for the Hopewell civilization, some 1,600-1,700 years ago just outside modern day Cincinnati. However, other scientists rejected the arguments.

September 7, 2023September 7, 2023 by Matt Williams

Another New Way to Measure Distance in the Universe: Baryon Acoustic Oscillations

An artist's concept of the latest, highly accurate measurement of the Universe from BOSS. The spheres show the current size of the "baryon acoustic oscillations" (BAOs) from the early universe, which have helped to set the distribution of galaxies that we see in the universe today. Galaxies have a slight tendency to align along the edges of the spheres — the alignment has been greatly exaggerated in this illustration. BAOs can be used as a "standard ruler" (white line) to measure the distances to all the galaxies in the universe. Credit: Zosia Rostomian, Lawrence Berkeley National Laboratory

Measuring cosmic distances is a major challenge thanks to the fact that we live in a relativistic Universe. When astronomers observe distant objects, they are not just looking through space but also back in time. In addition, the cosmos has been expanding ever since it was born in the Big Bang, and that expansion is accelerating. Astronomers typically rely on one of two methods to measure cosmic distances (known as the Cosmic Distance Ladder). On the one hand, astronomers rely on redshift measurements of the Cosmic Microwave Background (CMB) to determine cosmological distances.

Conversely, they will rely on local observations using parallax measurements, variable stars, and supernovae. Unfortunately, there is a discrepancy between redshift measurements of the CMB and local measurements, leading to what is known as the Hubble Tension. To address this, a team of astronomers from several Chinese universities and the University of Cordoba conducted a two-year statistical analysis of one million galaxies. From this, they’ve developed a new technique that relies on Baryon Acoustic Oscillations (BAO) to determine distances with a greater degree of precision.

September 7, 2023September 7, 2023 by Evan Gough

A Last-Minute Addition to the Solar Orbiter Allows it to See More Deeply into the Sun’s Atmosphere

A clever astronomer made a last minute hack to the Solar Orbiter's Extreme Ultraviolet Imager, allowing it to capture better images. Image Credit: ESA & NASA/Solar Orbiter/EUI Team; F. Auchère et al (2023); Solar disc: NASA/STEREO

Spacecraft instruments are highly specialized and can take years to design, build, and test. But a last-minute hack to one of the instruments on the ESA’s Solar Orbiter has allowed the spacecraft to take some difficult observations it would otherwise have been unable to take.

It’s all because of one astronomer and an instrument door.

September 7, 2023September 7, 2023 by Brian Koberlein

The Most Distant Galactic Field Lines Ever Seen

Mapping of the magnetic field in the distant 9io9 galaxy. Credit: ALMA (ESO/NAOJ/NRAO)/J. Geach et al.

The galaxies in our local Universe all have magnetic fields. Galactic magnetic fields can be generated by ionized gas within a galaxy, and these same magnetic fields affect the evolution of galaxies. But while modern galaxies have magnetic fields, did early ones? Astronomers are still trying to understand how galactic magnetic fields arise in young galaxies, but this can be a challenge without observational data. Now a team using data from the Atacama Large Millimeter/submillimeter Array (ALMA) has observed the magnetic field of a galaxy when the Universe was just 2.5 billion years old. The galaxy is known as 9io9. It takes 11 billion years for its light to reach us, making it the most distant galaxy for which we have observed a magnetic field.

September 6, 2023September 6, 2023 by Matt Williams

China Reveals Its Lunar Lander Design

Visualization of the ILRS, from the CNSA Guide to Partnership (June 2021). Credit: CNSA

Last May, as part of the nation’s growing presence in space, the China National Space Agency (CNSA) announced that it had established a Human Lunar Space Program that would send crewed missions to the Moon and culminate in the creation of a lunar base. This came shortly after China and Russia announced that they would be collaborating on future lunar missions, which included the creation of a base around the southern polar region. In June 2022, they announced that this base would be named the International Lunar Research Station (ILRS) and released a guide explaining how international partners could join.

On Thursday, August 31st, the China Manned Space Agency (CMSA) released artists’ renderings of their next-generation spacecraft and lunar lander. The spacecraft will consist of two sections, a reentry capsule, and a service section, while the lunar lander will include a landing section and a propulsion section. According to a statement released by the Agency, these vehicles will deliver crews to Low Earth Orbit (LEO) and allow China to send crewed missions to the lunar surface. The release of these images confirms what has been suspected for some time: that China fully intends to land taikonauts on the Moon before 2030.

September 6, 2023September 6, 2023 by Laurence Tognetti

What’s the Bare Minimum Number of People for a Mars Habitat?

Astronauts on Mars will need oxygen. There's oxygen in the atmosphere, but only small amounts. But there's lots of subterranean water on Mars, and that means there's lots of oxygen, too. (Credit: NASA)

A recent preprint paper examines the minimum number of people required to maintain a feasible settlement on Mars while accounting for psychological and behavioral factors, specifically in emergency situations. This study was conducted by a team of data scientists from George Mason University and holds the potential to help researchers better understand the appropriate conditions for a successful long-term Mars settlement, specifically pertaining to how those settlers will get along during all situations. But why is it important to better understand the psychological factors pertaining for a potential future Mars colony?

September 6, 2023September 6, 2023 by Evan Gough

As Night Falls, India’s Lunar Lander/Rover Goes to Sleep. Probably Forever

India's Pragyan lunar rover has been put into sleep mode after the end of its first lunar day. There's still a chance it could reawaken, but there's no guarantee. Image Credit: ISRO

India’s Chandrayaan-3 mission delivered its Vikram lander and Pragyan rover to the lunar surface on August 23rd. Now, as the lunar day ends two weeks later, the rover’s mission may be over. The Indian Space Research Organisation (ISRO) has put Pragyan into sleep mode.