Universe Today

March 20, 2021March 20, 2021 by Andy Tomaswick

Work Begins on Cleaning up Arecibo. The job Could Cost $50 Million

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

The collapse of Arecibo’s radio telescope was a devastating blow to the radio astronomy community. On December 1st, the suspended instrument platform came crashing down, destroying a large part of the receiver dish and the towers supporting the platform, as well as causing minor damage to some outlying buildings. Now the National Science Foundation (NSF), the government agency responsible for operating Arecibo is starting to pick up the pieces to figure out what’s next for the site, as they detailed in a brief report to Congress recently.

March 19, 2021March 19, 2021 by Matthew Cimone

An All-Sky X-Ray Survey Finds the Biggest Supernova Remnant Ever Seen

Composite Image of radio and x-ray observations of the Hoinga Supernova Remnant Credit: eROSITA/MPE (X-ray), CHIPASS/SPASS/N. Hurley-Walker, ICRAR-Curtin (Radio)

Our sky is missing supernovas. Stars live for millions or billions of years. But given the sheer number of stars in the Milky Way, we should still expect these cataclysmic stellar deaths every 30-50 years. Few of those explosions will be within naked-eye-range of Earth. Nova is from the Latin meaning “new”. Over the last 2000 years, humans have seen about seven “new” stars appear in the sky – some bright enough to be seen during the day – until they faded after the initial explosion. While we haven’t seen a new star appear in the sky for over 400 years, we can see the aftermath with telescopes – supernova remnants (SNRs) – the hot expanding gases of stellar explosions. SNRs are visible up to a 150,000 years before fading into the Galaxy. So, doing the math, there should be about 1200 visible SNRs in our sky but we’ve only managed to find about 300. That was until “Hoinga” was recently discovered. Named after the hometown of first author Scientist Werner Becker, whose research team found the SNR using the eROSITA All-Sky X-ray survey, Hoinga is one of the largest SNRs ever seen.

Composite of the X-ray (pink) and radio (blue) image of Hoinga. The X-rays discovered by eROSITA are emitted by the hot debris of the exploded progenitor star. Radio antennae on Earth detect radiation emission from electrons in the outer shell of the supernova
Credit: eROSITA/MPE (X-ray), CHIPASS/SPASS/N. Hurley-Walker, ICRAR-Curtin (Radio)

March 19, 2021May 7, 2021 by Matt Williams

Perseverance has Started Driving on Mars

On February 18th, 2021, NASA’s Perseverance rover landed in the Jezero Crater on Mars. Over the next two years of its primary mission, this robotic mission will carry on in the search for past life on Mars, obtaining soil and rock drill samples that will be returned to Earth someday for analysis. And as of March 4th, the rover conducted its first drive, covering 6.5 meters (21.3 feet) across the Martian landscape.

March 19, 2021March 19, 2021 by Brian Koberlein

There Could be Magnetic Monopoles Trapped in the Earth's Magnetosphere

A visualization of Earth's magnetosphere. Credit: NASA's Scientific Visualization Studio

Electricity and magnetism have a lot in common. They are connected by the unified theory of electromagnetism, and are in many ways two sides of the same coin. Both can exert forces on charges and magnetic fields. A changing electric field creates a magnetic field and vice versa. Elementary particles can possess electric and magnetic properties. But there is one fundamental difference.

March 18, 2021March 19, 2021 by Matt Williams

Oumuamua Isn’t an Alien Probe, Because Aliens can Learn Everything They Need About us With Telescopes

Artist’s impression of the interstellar object, `Oumuamua, experiencing outgassing as it leaves our Solar System. Credit: ESA/Hubble, NASA, ESO, M. Kornmesser

In the Fall of 2017, the first known interstellar object passed through the Solar System, triggering a revolution in astronomy. Because of the amonolous nature of the object, astronomers from all over the world were at a loss to explain what it was. Neither comet, nor asteroid, nor any other conventional object appeared to fit the bill, leading to all kinds of “exotic” explanations.

A particularly exotic explanation was offered by Harvard Professor Avi Loeb and his former postdoc (Dr. Shmuel Bialy), who hypothesized that ‘Oumuamua could have been an extraterrestrial lightsail. Whereas most rebuttal papers questioned the evidence presented, a new study by astrophysicist and UCLA emeritus professor Ben Zuckerman questioned something else: why would an extraterrestrial civilization want to send a probe our way?

March 18, 2021March 18, 2021 by Ralph Crewe

Oumuamua is Probably Very Similar to Pluto, Just From Another Star System

Artist's Concept of Oumuamua. Credit: William Hartmann

In 2017, the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) made history with the detection of a mysterious object called Oumuamua (Hawaiian for scout). Unlike countless other small objects that Pan-STARRS had detected before, Oumuamua seemed to originate from beyond the solar system. The first known interstellar object detected in the solar system, Oumuamua, with its odd trajectory, strange shape, and unusual acceleration, led to a flurry of activity in the astronomical community and an avalanche of wild claims of extraterrestrial space ships from various fringes of the media. A pair of papers published by Alan Jackson and Steven Desch of Arizona State University earlier this month reveals the best fit model for the identity of our extrasolar visitor. No, it isn’t aliens, but it’s pretty spectacular. Oumuamua seems to be a shard of a Pluto-like planet from another solar system!

March 18, 2021December 11, 2023 by Nancy Atkinson

Perseverance’s Landing Seen in Full Color, Thanks to Citizen Science

Incoming! Mars 2020 - Lander Vision System Camera shows the view of Jezero Crater from above. Colorized. Credit: NASA/JPL-Caltech/MSSS/Kevin M. Gill

A month on, we’re all still buzzing about the Perseverance rover’s perfect landing in Jezero Crater on Mars, back on February 18, 2021. Over the past few weeks, NASA has released more stunning imagery and footage of the landing, and since then the world-wide cadre of citizen scientists and image editing enthusiasts have been springing into action to enhance and augment all the incredible scenes captured by Perseverance’s collection of high-resolution cameras.

March 18, 2021March 18, 2021 by Scott Alan Johnston

Lightning Strikes Helped Life get an Early Start on Earth

So, you want to create life? You’re going to need some ingredients first. On Earth four billion years ago, you might find some of those ingredients in the impact craters of asteroid strikes (as long as you don’t get blown up in the blast yourself). A safer place to look, according to new research from the University of Leeds, might be in the sites of lightning strikes. Lightning is less destructive, more common, and creates equally useful minerals out of which you can build your early, single cellular life forms.

March 18, 2021March 18, 2021 by David Dickinson

Tracking Satellites Through GEOSat Eclipse Season

You can spot ‘GEOSat’ satellites in far-flung orbits… if you know exactly where and when to look.

Watch the sky long enough, and you’re bound to see one.

Seasoned observers are very familiar with seeing satellites in low Earth orbit, as these modern artificial sky apparitions lit by sunlight grace the dawn or dusk sky. Occasionally, you might even see a flare from a passing satellite, as a reflective solar panel catches the last rays of sunlight passing overhead just right…

March 17, 2021March 17, 2021 by Nancy Atkinson

Frosty Sand Dunes on Mars

Frosty dunes on Mars. Credit: NASA/JPL/UArizona.

Sand dunes on Mars are fascinating. They shift and move in different ways than they do on Earth, and they can grow to much more immense sizes than on our own planet. Several conditions contribute to the gigantic sand dunes and large fields of dunes that can form on the Red Planet, including its low gravity and air pressure.

Seasonal changes affect the Martian sand dunes, as well.