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Carbon from melting permafrost goes back to atmosphere

Kolyma region in the Siberian Arctic. Image Credit: Anatoly V. Lozhkin.

Kolyma region in the Siberian Arctic. Image Credit: Anatoly V. Lozhkin.

According to a new study, microbes eat the carbon and release it as CO2, where ends up back in the atmosphere and contributes to further warming.

What is dark energy?

How do we think about something we can’t see and don’t experience in our everyday lives, but seems to be pushing our universe apart ever faster? Image credit: NASA, ESA, G. Illingworth, D. Magee, and P. Oesch (University of California, Santa Cruz), R. Bouwens (Leiden University), and the HUDF09 Team, CC BY

How do we think about something we can’t see and don’t experience in our everyday lives, but seems to be pushing our universe apart ever faster? Image credit: NASA, ESA, G. Illingworth, D. Magee, and P. Oesch (University of California, Santa Cruz), R. Bouwens (Leiden University), and the HUDF09 Team, CC BY

Instead of pulling galaxies in our universe together, gravity seems to be driving them apart. How can gravity be repulsive, when our everyday experience shows it’s attractive? That’s why we need dark energy …

First visible light spectrum from exoplanet

Artist's concept of 51 Pegasi b orbiting its parent star.  Image via Dr. Seth Shostak/SPL.

Artist’s concept of 51 Pegasi b – sometimes unofficially called Bellerophon. It was the first exoplanet found orbiting a sunlike star. Now the first direct spectrum of light reflected from an exoplanet’s surface has been obtained from 51 Pegasi b. Image via Dr. Seth Shostak/SPL.

Why are astronomers excited about the first directly obtained visible light spectrum – or rainbow array of visible colors – bounced from the surface of an exoplanet? Look inside.

What’s the real deal with shark attacks?

Photo credit: C. Fallows

Photo credit: C. Fallows

Sharks are incredibly unlikely to bite you. They’re even less likely to kill you. However, we remain fascinated with their ability – and occasional proclivity – to do just that.

Ocean acidification drove Earth’s largest mass extinction

Computer artwork via the BBC

Computer artwork via the BBC

During the Permian–Triassic mass extinction event 252 million years ago, most life on Earth perished. Scientists have now obtained evidence that ocean acidification played a key role in the die-off.

Shortest lunar month of 2015 starts April 18

Simulated view of the cycle of the moon's phases from new moon to new moon. This cycle is known as the lunar month. From the years 1760 to 2200, the longest lunar month was 29 days 19 hours and 58 minutes and the shortest 29 days 6 hours and 34 minutes.

Simulated view of the moon’s phases. The period of time from new moon to new moon is known as the lunar month, lunation or synodic month. From the years 1760 to 2200, the longest lunar month spans 29 days 19 hours and 58 minutes (Dec. 9, 1787 to Jan. 8, 1778) while the shortest lasts for 29 days 6 hours and 34 minutes (June 12 to July 12, 1885).

The shortest lunar month this year happens in between the new moons of April 18 and May 18. This lunar month is only 29 days 9 hours and 16 minutes long, or 3 hours and 28 minutes shorter than the mean lunar month of 29 days 12 hours and 44 minutes.

Moon at perigee – nearest point to Earth – April 17

View larger. | Today's moon - an

Today’s moon – April 17, 2015 – an “old” moon visible in the east shortly before dawn. EarthSky Facebook friend Nikolaos Pantazis captured it over the Corinthian Gulf in Greece. Thank you, Nikolaos!

In April 2015, the moon sweeps to perigee – the moon’s closest point to Earth for the month – on April 17 at 3:53 UTC. That is April 16 at 10:53 p.m. CDT, so it’s possible that – by the time you read this – April’s perigee will have passed. The moon at this perigee is 224,329 miles (361,023 km) from Earth. We list the dates for this year’s 13 lunar apogees (farthest points) and 13 lunar perigees (nearest points), inside.

New Horizons’ first color pic of Pluto

This image of Pluto and its largest moon, Charon, was taken by the Ralph color imager aboard NASA's New Horizons spacecraft on April 9 Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

NASA’s New Horizons spacecraft acquired its first picture of Pluto and its largest moon, Charon, in color on April 9. It’s the first color image ever made of the Pluto system by a spacecraft on approach. Neither Pluto nor Charon is well resolved here, but their distinctly different appearances can already be seen. Image via NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Yesterday (April 14, 2015), NASA’s New Horizons spacecraft team released this tantalizing first color image of Pluto and its Texas-sized moon Charon. The team called this image a preliminary reconstruction, which they said will be refined later. New Horizons now only three months away from its historic sweep through the Pluto-Charon system in mid-July.

10 surprises about our solar system

This artist's concept puts solar system distances in perspective. The scale bar is in astronomical units, with each set distance beyond 1 AU representing 10 times the previous distance. One AU is the distance from the sun to the Earth, which is about 93 million miles or 150 million kilometers.  NASA's Voyager 1, humankind's most distant spacecraft, is around 125 AU.  Image via NASA/JPL-Caltech

This artist’s concept puts solar system distances in perspective. The scale bar is in astronomical units, with each set distance beyond 1 AU representing 10 times the previous distance. One AU is the distance from the sun to the Earth, which is about 93 million miles or 150 million kilometers. NASA’s Voyager 1, humankind’s most distant spacecraft, is around 125 AU. Image via NASA/JPL-Caltech.

A collection of 10 unexpected and intriguing facts about our solar system – our sun and its family of planets – you probably did not know!

Saturn storm of 2011: Best images

False-color image of great Saturn storm, taken shortly after it formed, in late 2010.

Cassini acquired the false-color image above shortly after astronomers noticed that a huge storm had formed on Saturn, in late December 2010. Saturn is shown in the infrared, viewed through a combination of three filters. The white and blue areas are clouds high in Saturn’s atmosphere. Yellow/green are mid-level clouds. Red/orange are deeper material. See more images inside.