Jupiters Aurora is a factor of 10 brighter than it should be based on Earth-like physics

Jupiter’s polar regions—anywhere between 10 and 30 times greater than any seen on Earth. Which they expected—everything’s bigger and badder on Jupiter. Trouble is, Jupiter’s aurora isn’t 10 or even 30 times stronger than Earth’s. It’s about a hundred times stronger. And there is no Earthly explanation for that discrepancy.

“Basically, the aurora is a factor of 10 brighter than it should be based on Earth-like physics,” Mauk says.

Whatever process accelerates Jupiter’s electrons up to a million electron volts is likely a total unknown. And Mauk, with the help of theorists and data from a few more orbits, is already on the trail of what that might be. “After orbit seven we saw what I would consider to be the smoking gun,” Mauk says. Mauk’s Jedi instrument saw the characteristic inverted V structure, but the electron excitement didn’t end there. As the electrical potential rose at the peak of the V, the acceleration went from coherent and linear to random—Mauk calls that a stochastic acceleration process. “Something goes unstable, and you start forming these waves,” Mauk says. “Some electrons gain a lot of energy, some just a little.”
What makes things get all unstable and random? Unclear.

Breaks Observed in the Mars Rover Wheel Treads

A routine check of the aluminum wheels on NASA’s Curiosity Mars rover has found two small breaks on the rover’s left middle wheel—the latest sign of wear and tear as the rover continues its journey, now approaching the 10-mile (16 kilometer) mark.

The mission’s first and second breaks in raised treads, called grousers, appeared in a March 19 image check of the wheels, documenting that these breaks occurred after the last check, on Jan. 27.”All six wheels have more than enough working lifespan remaining to get the vehicle to all destinations planned for the mission,” said Curiosity Project Manager Jim Erickson at NASA’s Jet Propulsion Laboratory, Pasadena, California. “While not unexpected, this damage is the first sign that the left middle wheel is nearing a wheel-wear milestone,”The monitoring of wheel damage on Curiosity, plus a program of wheel-longevity testing on Earth, was initiated after dents and holes in the wheels were seen to be accumulating faster than anticipated in 2013. Testing showed that at the point when three grousers on a wheel have broken, that wheel has reached about 60 percent of its useful life. Curiosity already has driven well over that fraction of the total distance needed for reaching the key regions of scientific interest on Mars’ Mount Sharp.Curiosity Project Scientist Ashwin Vasavada, also at JPL, said, “This is an expected part of the life cycle of the wheels and at this point does not change our current science plans or diminish our chances of studying key transitions in mineralogy higher on Mount Sharp.”Curiosity is currently examining sand dunes partway up a geological unit called the Murray formation. Planned destinations ahead include the hematite-containing “Vera Rubin Ridge,” a clay-containing geological unit above that ridge, and a sulfate-containing unit above the clay unit.

Source: NASA

The First View of TRAPPIST-1

See that black and white blob? That amorphous arrangement of pixels? That’s the newly discovered TRAPPIST-1 system, current darling of exoplanetary enthusiasts and alien-life optimists.

As announced last week, scientists identified seven Earth-sized planets orbiting the star, which appear to be rocky and temperate.

It’s an indirect picture of “shadows” of the planets, but a picture nonetheless. The gif is so, well, blobby, because it takes up such a tiny part of Kepler’s 95 megapixel camera: just 11 by 11 pixels.

“You absolutely are looking at a picture from a camera,” says Jessie Dotson, K2 Project Scientist, told me in a phone interview. “Kepler is essentially a really huge camera… but we don’t downlink all of that data. We just downlink the pixels, the part of the sky around the stars we’re interested in.”

“Imagine zooming into an image taken on your phone and only looking at 11×11 pixels,” Ethan Kruse, astronomer and graduate student at University of Washington explained via email.

Source: Here’s Our First View of TRAPPIST-1, the Alien Solar System With Earth-Sized Planets – Motherboard

Hubble Captures Brilliant Star Death

The Calabash Nebula, pictured here — which has the technical name OH 231.8+04.2 — is a spectacular example of the death of a low-mass star like the sun. This image taken by the NASA/ESA Hubble Space Telescope shows the star going through a rapid transformation from a red giant to a planetary nebula, during which it blows its outer layers of gas and dust out into the surrounding space. The recently ejected material is spat out in opposite directions with immense speed — the gas shown in yellow is moving close to one million kilometers per hour (621,371 miles per hour). Astronomers rarely capture a star in this phase of its evolution because it occurs within the blink of an eye — in astronomical terms. Over the next thousand years the nebula is expected to evolve into a fully-fledged planetary nebula. The nebula is also known as the Rotten Egg Nebula because it contains a lot of sulphur, an element that, when combined with other elements, smells like a rotten egg — but luckily, it resides over 5,000 light-years away in the constellation of Puppi

Source: Hubble Captures Brilliant Star Death in “Rotten Egg” Nebula | NASA