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Space Pictures This Week: Nebulae, Rockets, and a New Earth
By Dan Stone,
National Geographic News, 26 April 2013.

The Horsehead glows and Earth gets another twin in this week's best space pictures.

1. Horsehead Nebula Portrait

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This Hubble Space Telescope shot of the Horsehead Nebula, released April 19, was taken in celebration of the telescope's 23rd anniversary. Pictured in infrared wavelengths for the first time, the Horsehead is part of the larger constellation Orion.

The nebula is relatively close - just 1,500 light-years from Earth - which makes it a favourite for space photography focused on the formation of new stars. NASA scientists anticipate that despite Hubble's crystal-clear view, the new James Webb Space Telescope that will launch in 2018 will provide even more detailed views. (Read about travel to the stars in National Geographic magazine.)

2. Rocket Test

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Another in a growing number of space vehicles launched by private companies, the Antares rocket was sent skyward from the NASA Wallops Flight Facility in Virginia on April 21. The spacecraft, developed by Orbital Sciences Corporation, was designed to deliver a mock payload into orbit - the equivalent weight of a future spacecraft that could be launched from space. (Related: “5 Changes in Space Travel Since Yuri Gagarin's Flight.”)

3. Cloud Arc

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The Moderate Resolution Imaging Spectroradiometer on NASA's Terra satellite captured this image of a cloud formation in the eastern Pacific Ocean off the coast of California and Mexico on April 14.

The stratocumulus clouds sit low in the sky, appearing bulky and grey from the ground. The arc that sweeps downward through the image was likely a patch of clear sky caused by a disruption in air flow, perhaps by one of several islands near Los Angeles.

4. Aurora Spotting

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Depending on the time of year, watching for aurora borealis - or the northern lights - can be a popular activity in high latitudes. Here, the lights were visible in Stockholm, Sweden, on March 13 following a solar storm, and could be seen in the sky just before dusk. (See more pictures of auroras.)

5. Ancient Explosion

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The SN 1006 supernova was created by an exploding star in the year 1006, according to historical accounts. It was most likely a white dwarf that sucked up material from a companion star and exploded, or two white dwarf stars that merged and subsequently exploded.

A composite of ten x-ray images taken by NASA's Chandra x-ray observatory, released April 17, pieces together a tapestry of what the white dwarf star likely looked like when it exploded.

Type 1a supernovae, such as SN 1006, produce the same amount of energy, enabling researchers to estimate astronomical distances - which then allows them to gauge how fast the universe is expanding. (Related: “Most Distant Supernova May Shed Light on Dark Energy.”)

6. Another Earth?

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This conceptual artist rending, released April 18, shows Kepler-62f, an Earth-like planet nearly 1,200 light-years away. NASA scientists believe it orbits in the habitable zone for humans.

The planet is 40 percent larger than Earth and orbits its star, which is slightly cooler than Earth's sun, every 267 days.

The planet is believed to have a similar composition of water and land mass as our planet, but its exact components and mass are unknown, as is its current condition. Images and data received now of the planet capture light that left the planet more than a millennium ago.

[Source: National Geographic News. Edited.]