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Clues to the rapid rise of birds

Image credit: Jason Brougham (University of Edinburgh)

Image credit: Jason Brougham (University of Edinburgh)

“There was no moment in time when a dinosaur became a bird, and there is no single missing link between them,” said Steve Brusatte, who led the study.

Comet Siding Spring’s close encounter with Mars

One of the most anticipated astronomical events of 2014 is the close passage of Comet C/2013 A1 Siding Spring to the planet Mars on October 19, 2014. The comet’s tiny nucleus, or core, will miss Mars by about 82,000 miles (132,000 kilometers). But what a sight from Mars! The animation above shows Comet Siding Spring moving among the stars (yes, Mars sees the same patterns of stars we do from Earth). It’s the comet as seen from the location of Curiosity rover on Mars, now at the base of Mount Sharp in Mars’ Gale Crater, during Comet Siding Spring’s close flyby on October 19.

Curiosity rover drill pulls first taste from Mars mountain

This image from the Mars Hand Lens Imager (MAHLI) camera on NASA's Curiosity Mars rover shows the first sample-collection hole drilled in Mount Sharp, the layered mountain that is the science destination of the rover's extended mission. Image credit: NASA/JPL-Caltech/MSSS

This image from the Mars Hand Lens Imager (MAHLI) camera on NASA’s Curiosity Mars rover shows the first sample-collection hole drilled in Mount Sharp, the layered mountain that is the science destination of the rover’s extended mission. Image credit: NASA/JPL-Caltech/MSSS

The mission’s emphasis has now changed from drive, drive, drive to systematic layer-by-layer investigation. “Curiosity flew hundreds of millions of miles to do this,” said a JPL scientist.

Moon near Mars and star Antares on September 29

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As soon as darkness falls, look into the southwestern sky at nightfall to glimpse the planet Saturn rather close to the horizon. Saturn sets first, at relatively early evening. The moon, Mars and Antares follow the sun beneath the horizon by around mid-evening.

Autumn in Sweden

Photo credit: Jörgen Norrland Andersson

Photo credit: Jörgen Norrland Andersson

A fall day in Sweden. Photo by Jörgen Norrland Andersson.

Moon between Saturn and Mars at nightfall September 28

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At nightfall on September 28, the waxing crescent moon shines in between the planets Mars and Saturn. Mars lies to the east of the moon whereas Saturn shines to the west. The dark side of the waxing crescent moon points eastward, toward Mars and Antares, and the lit side westward, toward Saturn.

The water in your bottle might be older than the sun

Photo credit: University of Michigan

Photo credit: University of Michigan

Up to half of the water on Earth is likely older than the solar system itself, astronomers say. A new study in the journal Science suggests that much of the water on Earth and throughout our solar system likely originated as ices that formed in interstellar space. That would make it at least a million years older than the solar system.

A young galaxy in the local universe?

This image from the NASA/ESA Hubble Space Telescope shows a cosmic oddity, dwarf galaxy DDO 68. This ragged collection of stars and gas clouds looks at first glance like a recently-formed galaxy in our own cosmic neighborhood. But, is it really as young as it looks?

The Hubble Space Telescope captured this image of the dwarf galaxy DDO 68. It looks like a recently-formed galaxy in our own cosmic neighborhood, but is it really as young as it looks? The image is made up of exposures in visible and infrared light taken with Hubble’s Advanced Camera for Surveys. Image via NASA/ESA

The nearby dwarf galaxy DDO 68 – only 39 million light-years away – looks to be relatively youthful based on its structure, appearance, and composition. But its nearness to us in space would suggest that it’s not as young as it looks. A cosmic puzzle, inside.

Why is Antarctic sea ice increasing as Arctic sea ice declines?

This map, based on data from the AMSR2 sensor, shows Antarctic sea ice on September 19, 2014. Image credit: NASA

This map, based on data from the AMSR2 sensor, shows Antarctic sea ice on September 19, 2014. Image via NASA

Arctic sea ice continued its long-term decline in 2014. Meanwhile, sea ice on the other side of the planet was headed in the opposite direction. Why?

Is a solar flare the same thing as a CME?

Your Friday FAQ …

Solar flares and CMEs – coronal mass ejections – are both gigantic explosions of energy on the sun, but they’re not the same thing.