Astronomy Archives

November 19, 2020November 19, 2020 by Matt Williams

A 100-Meter Rotating Liquid Mirror Telescope on the Moon? Yes Please.

New results from the NASA/ESA Hubble Space Telescope suggest the formation of the first stars and galaxies in the early Universe took place sooner than previously thought. A European team of astronomers have found no evidence of the first generation of stars, known as Population III stars, when the Universe was less than one billion years old. This artist’s impression presents the early Universe. Image Credit: ESA/Hubble, M. Kornmesser.

In the coming years, some truly awesome next-generation telescopes are going to be gathering their first light. Between space telescopes like James Webb and Nancy Grace Roman, and ground-based telescopes like the Extremely Large Telescope (ELT) and the Giant Magellan Telescope (GMT), astronomers will be able to study aspects of the Universe that were previously inaccessible.

For instance, there are Population III stars, which are the first stars to have formed in the Universe. These stars are not observable in visible light and even next-generation facilities (like those mentioned above) will not be able to see them. But according to a team led by NASA Hubble Fellow Anna Schauer, the solution could be to build what she has named the “Ultimately Large Telescope” (ULT) on the Moon.

November 19, 2020November 19, 2020 by Matt Williams

Earth and the Moon Might Have Captured an Old Upper Stage Rocket

The crescent Earth rises above the lunar horizon in this spectacular photograph taken by the Apollo 17 crew in lunar orbit in December, 1972, during NASA’s final lunar landing mission in the Apollo program. Credit: NASA. Image editing and enhancement: Kevin Gill.

Back in September, the Pan-STARRS1 survey telescope noticed an object that followed a slight but distinctly curved path in the sky, a telltale sign that it was captured by Earth’s gravity. Initially, this object was thought to be a near-Earth Asteroid (NEA) and was given a standard designation by the Minor Planet Center (2020 SO). However, the Center for Near-Earth Object Studies (CNEOS) at NASA JPL had another theory.

Based on its orbit and the way solar radiation appeared to be pushing it off course, NASA scientists have since concluded that the object might actually be the spent upper stage booster of the Centaur rocket that launched the Surveyor 2 spacecraft towards the Moon in 1966. This finding could have implications for future surveys that pick up mysterious objects near Earth (‘Oumuamua occur).

November 18, 2020November 18, 2020 by Matt Williams

Past Supernovae Could be Written Into Tree Rings

A bubble of gas expanding at roughly 11 million miles per hour created by the shockwave from a supernova. Credit: NASA

When stars reach the end of their lifespan, they undergo gravitational collapse at their cores. The type of explosion that results is one of the most awesome astronomical events imaginable and (on rare occasions) can even be seen with the naked eye. The last time this occurred was in 1604 when a Type Ia supernova took place over 20,000 light-years away – commonly-known as Kepler’s Supernova (aka. SN1604)

Given the massive amounts of radiation they release, past supernovae are believed to have played a role in the evolution of our planet and terrestrial life. According to new research by CU Boulder geoscientist Robert Brakenridge, these same supernovae may have left traces in our planet’s biology and geology. These findings could have implications given fears that Betelgeuse might be on the verge of going supernova.

November 17, 2020November 17, 2020 by David Dickinson

A Record Close Shave: Asteroid 2020 VT4 Just Skimmed by Earth

Wow. A low-flying space rock set a record last Friday (appropriately, the 13^th), when 2020 VT4 passed just under 400 kilometers (250 miles) over the Southern Pacific.

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.