Universe Today

April 14, 2021April 14, 2021 by Matt Williams

If you Want to Move an Asteroid, you Need the Right Kind of Nuclear Explosion

Artist's concept of a large asteroid passing by the Earth-Moon system. Credit: A combination of ESO/NASA images courtesy of Jason Major/Lights in the Dark.

Using nuclear devices to deflect or disrupt an asteroid. Sounds a bit crazy, no? Maybe a little too Hollywood? And yet, detonating nukes in space may be necessary someday for the sake of planetary defense. In order for this method to be effective, scientists need to work out all the particulars in advance. That means knowing how much force will be necessary depending on the mass and trajectory of the asteroid.

Recently, a research collaboration between Lawrence Livermore National Laboratory (LLNL) and the Air Force Institute of Technology (AFIT) investigated how the energy output of a nuclear detonation could affect the path of an asteroid. This consisted of modeling different nuclear reactions (fission or fusion) to determine the neutron energy generated, which could potentially pave the way for a new type of asteroid redirect mission (ARM).

April 14, 2021April 14, 2021 by Brian Koberlein

Finding Oxygen on an Alien World Doesn't Always Mean There's Life There

Artist concept of the planetary system Kepler 62. Credit: Danielle Futselaar - SETI Institute

We now know the universe is filled with planets. By one estimate, there are more than 20 billion Earth-like worlds in our galaxy alone. But how many of them are likely to have life? And how would we know if they do? Unless they happen to send us a very clear message directly, the most likely way we’ll discover exoplanet life is by looking at their atmospheres.

April 14, 2021April 14, 2021 by Nancy Atkinson

100-meter Asteroid Created a Strange Impact Event in Antarctica 430,000 Years Ago

Mocked up illustration of touchdown impact on Antarctica. Credit: Mark A. Garlick.

The effects of ancient asteroid impacts on Earth are still evident from the variety of impact craters across our planet. And from the Chelyabinsk event back in 2013, where an asteroid exploded in the air above a Russian town, we know how devastating an “airburst” event can be.

Now, researchers in Antarctica have discovered evidence of a strange intermediate-type event – a combination of an impact and an airburst. The event was so devastating, its effects are still apparent even though it took place 430,000 years ago.

April 14, 2021April 15, 2021 by David Dickinson

Galileo Sunspot Sketches Versus Modern ‘Deep Learning’ AI

A new study turns modern ‘deep learning’ techniques on Galileo’s early sketches of the Sun.

It’s a fascinating thought to consider.

What exactly did the Sun look like, centuries ago? What would we see, if astronomers back in the time of Kepler and Galileo had modern technology monitoring the Sun across the electromagnetic spectrum, available to them?

April 13, 2021April 13, 2021 by Nancy Atkinson

Earth Gains 5,200 Tons of Dust From Space Every Year

Electron micrograph of a Concordia micrometeorite extracted from Antarctic snow at Dome C. Credit and copyright: Cécile Engrand/Jean Duprat.

Whenever I wipe the dust off my coffee table or catch a glimpse of dust motes floating in sunlight, my spacey mind always wonders, is any of that cosmic dust?

It just might be. But the amount of space dust that lands on our planet every year might surprise you.

April 12, 2021April 12, 2021 by Matt Williams

The Same Technology Could Search for Microbes in Mars Rocks or Under the ice on Europa

Ever since it landed in the Jezero Crater on Feb. 18^th, 2021, the Perseverance rover has been prepping its scientific instruments to begin searching for signs of past life on the Red Planet. These include spectrometers that will scan Martian rocks for organics and minerals that form in the presence of water and a caching system that will store samples of Martian soil and rock for retrieval by a future mission.

These telltale indicators could be signs of past life, which would most likely take the form of fossilized microbes. In the near future, a similar instrument could be used to search for present-day extraterrestrial life. It’s known as the Wireline Analysis Tool for the Subsurface Observation of Northern ice sheets (WATSON), and could be used to find evidence of life inside “ocean worlds” like Europa, Enceladus, and Titan.

April 12, 2021April 12, 2021 by Andy Tomaswick

Trojan Mission Lucy Tested its Solar Panels for the First Time. Those Things are Huge

Space missions often have to go where the sun don’t shine. Or at least where it shines very faintly. That is particularly important if the mission draws its power from the sun. Luckily, engineers have a way of dealing with that problem – just make really really big solar panels. That is exactly what they did for Lucy, a mission to visit the Trojan asteroids around Jupiter. Those sails have now been tested on the ground, and they are magnificent.

April 12, 2021April 12, 2021 by Matt Williams

Gaia Finds 12 Examples of Einstein Crosses; Galaxies Being Gravitationally Lensed so we see Them Repeated 4 Times

Credit and : R. Hurt (IPAC/Caltech)/The GraL Collaboration

In 1915, Einstein put the finishing touches on his Theory of General Relativity (GR), a revolutionary new hypothesis that described gravity as a geometric property of space and time. This theory remains the accepted description of gravitation in modern physics and predicts that massive objects (like galaxies and galaxy clusters) bend the very fabric of spacetime.

As result, massive objects (like galaxies and galaxy clusters) can act as a lens that will deflect and magnify light coming from more distant objects. This effect is known as “gravitational lensing,” and can result in all kinds of visual phenomena – not the least of which is known as an “Einstein Cross.” Using data from the ESA’s Gaia Observatory, a team of researchers announced the discovery of 12 new Einstein Crosses.

April 12, 2021April 12, 2021 by Brian Koberlein

Brown Dwarfs can Spin so Fast They Almost Tear Themselves Apart

Comparing the rotation of a brown dwarf with Jupiter and Saturn. Credit: Robert Hurt (IPAC/Caltech)

We tend to image planets as spheres. Held together by gravity, the material of a planet compresses and shifts until gravity and pressure reach a balance point known as hydrostatic equilibrium. Hydrostatic equilibrium is one of the defining characteristics of a planet. If a planet were stationary and of uniform density, then at equilibrium, it would be a perfect sphere. But planets rotate, and so even the largest planets aren’t a perfect sphere.

April 12, 2021April 12, 2021 by Scott Alan Johnston

OSIRIS-REx Did One Last Close Flyby of Asteroid Bennu. It’s Almost Time to Come Home

After more than two years in orbit around asteroid Bennu, NASA’s OSIRIS-REx spacecraft is ready to come home. It’s bringing with it a pristine sample of space rocks that geologists here on Earth are eager to study up close. The sample will arrive in September 2023, but we won’t have to wait nearly that long for new data from OSIRIS-REx. Last week, the probe carried out one final flyby of Bennu, in an effort to photograph the sample collection site. The photographs are being downlinked now, and should be here by midweek.

If you’ve been following the OSIRIS-REx mission, you probably already know why scientists are keen to see these photographs, but if you haven’t, hold on to your hats – it’s a wild story.