Exciting New Views Of Opportunity’s Remarkable Landing Site

The HiRise camera aboard NASA’s Mars Reconnaissance Orbiter has captured color images of the Opportunity’s 2004 Hole In One landing site inside Eagle Crater.
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First Detailed Image Of Accretion Disk Around A Young Star

For the first time ever, an international team of astronomers – using the ALMA array – have taken a clear image of an accretion disk around a young protostar.
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Are Drylanders The Minority On Habitable Worlds?

We assume that habitable exoplanets will have significant land masses, because that’s what we have on Earth. Are we wrong?
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Hubble’s cosmic bubbles

Hubble has revealed a few of the tenuous threads comprising Sh2-308, a faint and wispy shell of gas located 5,200 light-years away in Canis Major. …

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Earth Beams From Between Saturn’s Rings in New Cassini Image

Cassini took this rare photo of the Earth and moon on April 12 just before the start of its daring Grand Finale mission this weekend.
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Importance of fingering convection for accreting white dwarfs in the framework of full evolutionary calculations

Vol. 601
In section 7. Stellar structure and evolution

Importance of fingering convection for accreting white dwarfs in the framework of full evolutionary calculations: the case of the hydrogen-rich white dwarfs GD133 and G29-38

by F. C. Wachlin, G. Vauclair, S. Vauclair, L. G. Althaus, A&A, 601, A13

alt

The presence of heavy elements in hydrogen-layer white dwarfs (the most
common variety) several decades ago led to a number of different hypotheses
regarding the source of metals. One of the more popular ideas currently, is
linked to the discovery of debris disks around some white dwarfs: a source
of heavy elements could be the disruption of planetisimals that are close to
the tidal radius of the white dwarf. In order to link the composition of disrupted planetesimals to the white dwarf surface composition, a number of
processes need to be taken into consideration, especially those that influence
the mixing of any accreted material. Wachlin and collaborators have carried
out such a study, focussing on the most important of these: the double-diffusive
instability that results from the accretion of heavy elements. They found that
the accretion rates required to explain the abundances in two well-observed white dwarfs, G 29-38 and GD 133, are higher by 1.7 to 2 dex presenting a challenge to current observations, and implying the disruption of significantly more massive bodies than previously considered.

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Is This The Exoplanet Where Life Will First Be Found?

An international team of scientists has found another rocky planet (LHS 1140b) orbiting a nearby red dwarf star. And it looks to be our best bet to date for finding a habitable exoplanet.
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Opportunity Leaving ‘Tribulation’ Behind

You’d have to be an intrepid explorer to investigate something named ‘Cape Tribulation’. Opportunity, NASA’s long-lived rover on Mars’ surface, has been just that. But Opportunity is now leaving Cape Tribulation behind, after being in that area since late 2014, or for about 30 months. Cape Tribulation is the name given to a segment of […]
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Mars Missions Need To Be Neat Freaks At Key Sites

A new study from the Finnish Meteorological Institute shows how jettisoned hardware and Martian weather could make a dangerous combination!
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Light rays from a supernova bent by the curvature of space-time around a galaxy

Astronomers have detected for the first time multiple images from a gravitationally lensed Type Ia supernova. The new observations suggest promising new avenues for the study of the accelerated expansion of the universe, gravity and distribution of dark matter in the universe. …

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The Bubbly Streams Of Titan

Titan’s so-called “magic islands” are not islands at all, but nitrogen bubbles, according to researchers at NASA’s Jet Propulsion Laboratory.
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