Posted on by Matt Williams

ExoMars Sees the Martian Atmosphere Glowing Green

Credit: ESA

In the course of studying Mars, scientists have come to identify some key similarities to Earth’s own. One notable example is the way our atmospheres interact with sunlight to produce dazzling displays of energy. On Earth, these include not just the aurorae near the polar regions (Aurora Borealis and Australis), but the constant green glow that is the result of oxygen molecules interacting with sunlight (aka. “airglow”).

On Earth, airglow can be seen “edge-on” from space, as exemplified by the many spectacular images that are taken by astronauts aboard the International Space Station (ISS). This phenomenon was recently observed around Mars for the first time by the ESA’s Trace Gas Orbiter (TGO), which arrived at Mars in 2016 a part of the ExoMars program. Like aurorae, this observation is yet another example of how Mars is “Earth’s Twin.”

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Posted on by Matt Williams

Searching for the End of the Universe’s “Dark Age”

A ‘radio colour’ view of the sky above the Murchison Widefield Array radio telescope, part of the International Centre for Radio Astronomy Research (ICRAC). Credit: Radio image by Natasha Hurley-Walker (ICRAR/Curtin) and the GLEAM Team. MWA tile and landscape Credit: ICRAR/Dr John Goldsmith/Celestial Visions

According to the most widely accepted cosmological theories, the first stars in the Universe formed a few hundred million years after the Big Bang. Unfortunately, astronomers have been unable to “see” them since their emergence coincided during the cosmological period known as the “Dark Ages.” During this period, which ended about 13 billion years ago, clouds of gas filled the Universe that obscured visible and infrared light.

However, astronomers have learned that light from this era can be detected as faint radio signals. It’s for this reason that radio telescopes like the Murchison Widefield Array (MWA) were built. Using data obtained by this array last year, an international team of researchers is scouring the most precise radio data to date from the early Universe in an attempt to see exactly when the cosmic “Dark Ages” ended.

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Posted on by Evan Gough

Why Pulsars Are So Bright

Pulsars are fast-spinning neutron stars that emit narrow, sweeping beams of radio waves. A new study identifies the origin of those radio waves. NASA’s Goddard Space Flight Center
Pulsars are fast-spinning neutron stars that emit narrow, sweeping beams of radio waves. A new study identifies the origin of those radio waves. NASA’s Goddard Space Flight Center

When pulsars were first discovered in 1967, their rhythmic radio-wave pulsations were a mystery. Some thought their radio beams must be of extraterrestrial origin.

We’ve learned a lot since then. We know that pulsars are magnetized, rotating neutrons stars. We know that they rotate very rapidly, with their magnetic poles sending sweeping beams of radio waves out into space. And if they’re aimed the right way, we can “see” them as pulses of radio waves, even though the radio waves are steady. They’re kind of like lighthouses.

But the exact mechanism that creates all of that electromagnetic radiation has remained a mystery.

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Posted on by Matt Williams

What Does it Mean to Be a Space Architect?

Artist conception of a Hi-SEAS habitation dome. Credit: Blue Planet Research/Bryan Christie Design

Here on Earth, the concept of architecture (and those who specialize in it), is pretty clear and straightforward. But in space, human beings have comparatively little experience living and working in habitats. For the past sixty years, multiple space stations have been sent to Low Earth Orbit (LEO), which include the now-defunct Salyut stations, Skylab, and Mir, as well as the present-day International Space Station (ISS).

But in the near the future, we hope to build stations and commercial habitats in LEO, on the surface of the Moon, and Mars. In addition to needing a steady supply of food, water, and other necessities, measures will need to be taken to ensure the psychological well-being of their crews. In a recent article, Stellar Amenities founder and CEO (a space architect herself!) Anastasia Prosina explored how space architecture can meet these needs.

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Posted on by David Dickinson

Book Review: Atlas of Solar Eclipses 2020 to 2045

Love solar eclipses? It’s the main question on everyone’s mind post-totality, once the all-too-brief darkness gives way back to light of day…

When’s the next total solar eclipse?

Anyone who has stood in the shadow of the Moon during totality knows the thrill of a total solar eclipse. Now, there’s great new atlas for planning your next great eclipse-chasing adventure. The Atlas of Solar Eclipses 2020 to 2045 by eclipse-chaser and cartographer Michael Zeiler and Michael E. Bakich is an indispensable astronomical resource.

This guide covers every solar eclipse out to 2045, starting with this weekend’s annular eclipse across southern Asia on June 21, 2020, all the way out to the total solar eclipse of August 12, 2045 crossing North America, the Caribbean and South America.

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Posted on by Matt Williams

Pulsars Confirm One of Einstein’s Best Ideas, That Freefall Really Feels Like You’re Experiencing a Lack of Gravity

This artist’s impression shows the exotic double object that consists of a tiny, but very heavy neutron star that spins 25 times each second, orbited every two and a half hours by a white dwarf star. The neutron star is a pulsar named PSR J0348+0432 that is giving off radio waves that can be picked up on Earth by radio telescopes. Although this unusual pair is very interesting in its own right it is also a unique laboratory for testing the limits of physical theories. This system is radiating gravitational radiation, ripples in spacetime. Although these waves cannot be yet detected directly by astronomers on Earth they can be detected indirectly by measuring the change in the orbit of the system as it loses energy. As the pulsar is so small the relative sizes of the two objects are not drawn to scale.

Six and a half decades after he passed away, famed theoretical physicist Albert Einstein is still being proven right! In addition to General Relativity (GR) being tested under the most extreme conditions, lesser-known aspects of his theories are still being validated as well. For example, GR predicts that gravity and inertia are often indistinguishable, in what is known as the gravitational Strong Equivalence Principle (SEP).

Thanks to an international team of researchers, it has been proven under the strongest conditions to date. By precisely tracking the motion of a pulsar, the team demonstrated that gravity causes neutron stars and white dwarf stars to fall with equal accelerations. This confirms Einstein’s prediction that freefall accurately simulates zero-gravity conditions in all inertial reference frames.

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Posted on by Evan Gough

Barred Spiral Galaxy NGC 2608, Surrounded by Many Many Other Galaxies

Looking deep into the Universe, the NASA/ESA Hubble Space Telescope catches a passing glimpse of the numerous arm-like structures that sweep around this barred spiral galaxy, known as NGC 2608. Appearing as a slightly stretched, smaller version of our Milky Way, the peppered blue and red spiral arms are anchored together by the prominent horizontal central bar of the galaxy. In Hubble photos, bright Milky Way stars will sometimes appear as pinpoints of light with prominent lens flares. A star with these features is seen in the lower right corner of the image, and another can be spotted just above the pale centre of the galaxy. The majority of the fainter points around NGC 2608, however, lack these features, and upon closer inspection they are revealed to be thousands of distant galaxies. NGC 2608 is just one among an uncountable number of kindred structures. Similar expanses of galaxies can be observed in other Hubble images such as the Hubble Deep Field which recorded over 3000 galaxies in one field of view.

Meet NGC 2608, a barred spiral galaxy about 93 million light years away, in the constellation Cancer. Also called Arp 12, it’s about 62,000 light years across, smaller than the Milky Way by a fair margin. The Hubble Space Telescope captured this image with its Wide-Field Camera 3 (WFC3).

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Posted on by Evan Gough

Newborn Exoplanets can be Completely Stripped of Their Atmosphere by Stars

Artist's conception of exoplanet systems that could be observed by PLAnetary Transits and Oscillations of stars (PLATO), a European Space Agency telescope. Credit: ESA - C. Carreau

Newborn exoplanets can have a tough life. They may form an atmosphere, but that atmosphere can be doomed. Their stars can emit intense X-ray and UV radiation, stripping away those atmospheres and laying their surfaces bare.

A team of researchers from the Leibniz Institute for Astrophysics looked at a family of four newborn sibling planets, and tried to understand how their star strips away their gaseous envelopes.

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