Astronomy Archives

November 16, 2020November 16, 2020 by Matt Williams

New Horizons Saw the Universe With Even Less Light Pollution than Hubble’s View

Artist's impression of New Horizons' close encounter with the Pluto–Charon system. Credit: NASA/JHU APL/SwRI/Steve Gribben

In July of 2015, NASA’s New Horizons probe made history when it became the first mission ever to conduct a close flyby of Pluto. This was followed by the spacecraft making the first-ever encounter with a Kuiper Belt Object (KBO) – known as Arrokoth (aka. 2014 MU69) – on Dec.31st, 2018. In addition, its unique position in the outer Solar System has allowed astronomers to conduct rare and lucrative science operations.

This has included parallax measurements of Proxima Centauri and Wolf 359, the two closest stars to the Solar System. In addition, a team of astronomers led by the National Optical Astronomy Observatory (NOAO) and Southwest Research Institute (SwRI) used archival data from the probe’s Long Range Reconnaissance Imager (LORRI) to conduct measurements of the Cosmic Optical Background (COB).

November 15, 2020November 15, 2020 by Matt Williams

What Role do Radioactive Elements Play in a Planet’s Habitability?

Illustration of Kepler-186f, a recently-discovered, possibly Earthlike exoplanet that could be a host to life. (NASA Ames, SETI Institute, JPL-Caltech, T. Pyle) — This is Kepler 186f, an exoplanet in the habitable zone around a red dwarf. We've found many planets in their stars' habitable zones where they could potentially have surface water. But it's a fairly crude understanding of true habitability. Image Credit: NASA Ames, SETI Institute, JPL-Caltech, T. Pyle)

To date, astronomers have confirmed the existence of 4,301 extrasolar planets in 3,192 star systems, with another 5,650 candidates awaiting confirmation. In the coming years, next-generation telescopes will allow astronomers to directly observe many of these exoplanets and place tighter constraints on their potential habitability. In time, this could lead to the discovery of life beyond our Solar System!

The only problem is, finding evidence of life requires that we know what to look for. According to a new study by an interdisciplinary team of scientists from the University of California Santa Cruz (UCSC), radioactive elements might play a role in planetary habitability. Future studies of rocky exoplanets, they argue, should therefore look for specific isotopes that indicate the presence of long-lived elements like thorium and uranium.

November 14, 2020November 14, 2020 by Matt Williams

The Average Temperature of the Universe has Been Getting Hotter and Hotter

An illustration of cosmic expansion. Credit: NASA's Goddard Space Flight Center Conceptual Image Lab

For almost a century, astronomers have understood that the Universe is in a state of expansion. Since the 1990s, they have come to understand that as of four billion years ago, the rate of expansion has been speeding up. As this progresses, and the galaxy clusters and filaments of the Universe move farther apart, scientists theorize that the mean temperature of the Universe will gradually decline.

But according to new research led by the Center for Cosmology and AstroParticle Physics (CCAPP) at Ohio State University, it appears that the Universe is actually getting hotter as time goes on. After probing the thermal history of the Universe over the last 10 billion years, the team concluded that the mean temperature of cosmic gas has increased more than 10 times and reached about 2.2 million K (~2.2 °C; 4 million °F) today.

November 13, 2020November 13, 2020 by Matt Williams

Europa’s Nightside Glows in the Dark

This illustration of Jupiter's moon Europa shows how the icy surface may glow on its nightside, the side facing away from the Sun. Variations in the glow and the color of the glow itself could reveal information about the composition of ice on Europa's surface. Credit: NASA/JPL-Caltech

In a few years, NASA will be sending a spacecraft to explore Jupiter’s icy moon Europa. Known as the Europa Clipper mission, this orbiter will examine the surface more closely to search for plume activity and evidence of biosignatures. Such a find could answer the burning question of whether or not there is life within this moon, which is something scientists have speculated about since the 1970s.

In anticipation of this mission, scientists continue to anticipate what it will find once it gets there. For instance, scientists from NASA’s Jet Propulsion Laboratory recently conducted a study that showed how Europa might glow in the dark. This could be the result of Europa constantly being pummeled with high-energy radiation from Jupiter’s magnetic field, the study of which could tell scientists more about the composition of Europa’s ice.

November 12, 2020November 12, 2020 by David Dickinson

From a Tempest to a Trickle: Prospects for the 2020 Leonid Meteor Shower

Following the Leonid meteors in 2020.

We witnessed an amazing astronomical spectacle in the early morning skies over the Kuwaiti desert in November 1998. That year, the Leonid meteors put on a spectacular display, topping an estimated 1,000 meteors per hour near sunrise. On most years, however, the Lion whimpers with a few paltry meteors per hour, but once every 33 years or so, the mighty Leonids can roar with an amazing display reaching storm level proportions.

November 11, 2020November 11, 2020 by Andy Tomaswick

Meteorite Tells Us About Water on Mars 4.4 Billion Years Ago

Image of the NWA7533 meteorite that was the subject of the study. Credit: University of Copenhagen / Deng et all.

Meteorites often offer terrific glimpses into worlds we are unable to otherwise access. Sometimes those worlds are simply fragments of asteroids that didn’t burn up when they entered the atmosphere. But sometimes, they come from the Moon or Mars. Part of what makes these types of meteorites interesting is that they don’t necessarily come from what we now think of as two of our nearest neighbors. Fragments of meteorites that end up on Earth act as a kind of time capsule, allowing us to understand the geological environment of the world when the meteorite was formed.

A meteorite found in the Sahara desert a few years ago is exactly that type of time capsule. Named NWA 7533 (named after “North West Africa”, not the 80s rap group), this meteorite came from Mars about 4.4 billion years ago. A team led by Profs Zhengbin Deng at the University of Copenhagen and Takashi Mikouchi at the University of Tokyo have found evidence that the impact the created NWA 7533 most likely took place in the presence of water.

November 11, 2020November 11, 2020 by Nancy Atkinson

A Second Cable has Failed at Arecibo, Causing Even More Damage to the Radio Observatory

The Arecibo Radio Telescope. Though it's decommissioned now, Arecibo Data may explain 1977's mysterious Wow! Signal. Image Credit: UCF

Another main cable that supports the Arecibo Observatory broke last week, falling onto the reflector dish and causing more damage. This is the second time a cable has snapped on the iconic radio observatory in just three months.

The new damage is an unfortunate and devastating setback for the observatory, just as repairs from the first accident were about to begin.

November 10, 2020November 10, 2020 by Matt Williams

The Driest Place on Earth Could Help Predict How Life Might be Surviving on Mars

Future missions could determine the presence of past life on Mars by looking for signs of extreme metal-metabolizing bacteria. Credit: NASA.

In the next few years, Mars will be visited by three new rovers, the Perseverance, Tianwen-1, and Rosalind Franklin missions. Like their predecessors – Pathfinder and Sojourner, Spirit and Opportunity, and Curiosity – these robotic missions will explore the surface, searching for evidence of past and present life. But even after years of exploring, an important question remains: where is the best place to look?

To date, all attempts to find evidence of life on the surface have yielded nothing, owing to the fact that the Martian environment is extremely cold, desiccated, and irradiated. According to a new study by an international team of researchers led by Cornell University and the Centro de Astrobiología in Madrid, the Atacama desert in the mountains of Chile could hold the answer.

November 8, 2020November 8, 2020 by Paul M. Sutter

Massive stars get kicked out of clusters

A "super star cluster", Westerlund 1, which is about 16,000 light-years from Earth. It can be found in the southern constellation of Ara. The picture was taken from the European Southern Observatory's VLT Survey Telescope. Credit: ESO/VPHAS+ Survey/N. Wright

The largest stars in the universe tend to be loners, and new research points to the reason why. Although massive stars are born in clusters of many smaller brethren, they quickly get kicked out, forced to spend their lives alone.

November 7, 2020November 9, 2020 by Matt Williams

Vera Rubin Should be Able to Detect a Couple of Interstellar Objects a Month

The Vera C. Rubin Observatory is under construction at Cerro Pachon, in Chile. This image shows construction progress in late 2019. The VCO should be able to spot interstellar objects like Oumuamua. Image Credit: Wil O'Mullaine/LSST CC BY-SA 4.0, https://en.wikipedia.org/w/index.php?curid=62504391

The Vera C. Rubin Observatory, formerly the Large Synoptic Survey Telescope (LSST), will commence operations sometime next year. Not wanting to let a perfectly good acronym go to waste, its first campaign will be known as the Legacy Survey of Space and Time (LSST). This ten-year survey will study everything from dark matter and dark energy to the formation of the Milky Way, and small objects in our Solar System.

According to a new study by Amir Siraj and Prof. Abraham Loeb of Harvard University, another benefit of this survey will be the discovery of interstellar objects that regularly enter the Solar Systems. These results, when combined with physical characterizations of the objects, will teach us a great deal about the origin and nature of planetary systems (and could even help us spot an alien probe or two!)