Having Fun with the Equation of Time

by David Dickinson on July 25, 2014

An analemma of the Sun, taken from Budapest, Hungary over a one year span. (Courtesy of György Soponyai, used with permission).

An analemma of the Sun, taken from Budapest, Hungary over a one year span. (Courtesy of György Soponyai, used with permission).

If you’re like us, you might’ve looked at a globe of the Earth in elementary school long before the days of Google Earth and wondered just what that strange looking figure eight thing on its side was.

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If you spent 120 days cooped up in a small habitat with six people, what’s the first thing you’d want to do upon emerging? Celebration would likely be one of them, and you can watch the festivities as the HI-SEAS crew leaves their Mars simulation later today.

The broadcast takes place between 2 p.m. EDT and 4 p.m. EDT (6 p.m. and 8 p.m. UTC) and you can watch everything above. As with all live events, the schedule can always change at the last minute.

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Expedition 40 astronaut Alexander Gerst took this photo of the Israel and Gaza regions in July 2014 while explosions took place below (which are not visible in the photo). Credit: Alexander Gerst/Twitter

Expedition 40 astronaut Alexander Gerst took this photo of the Israel and Gaza regions in July 2014 while explosions took place below (which are not visible in the photo). Credit: Alexander Gerst/Twitter

From his perch aboard the International Space Station, Alexander Gerst took this photo this week and said he could spot explosions and rockets in the blackness below. The location made him realize things were grim: it was over the Gaza and Israel region.

After the photo went viral on Twitter (it’s been shared nearly 40,000 times to date), Gerst wrote a blog post reflecting on what he saw. He acknowledged the violence wasn’t visible in the photo, but said he could still see it.

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Video: Warp Into A Star Nursery 3,000 Light Years Away

by Elizabeth Howell on July 25, 2014

Zoom! This video brings you up close to a region where a bunch of stars are being born. This new video from the European Southern Observatory shows a so-called an HII region made up of hydrogen gas, which is a common feature of nurseries. Another famous example is the Eagle Nebula’s Pillars of Creation.

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Mapping Dark Matter 4.5 Billion Light-years Away

by Shannon Hall on July 25, 2014

This image shows the galaxy MCS J0416.1–2403, one of six clusters targeted by the Hubble Frontier Fields programme. The blue in this image is a mass map created by using new Hubble observations combined with the magnifying power of a process known as gravitational lensing. In red is the hot gas detected by NASA’s Chandra X-Ray Observatory and shows the location of the gas, dust and stars in the cluster. The matter shown in blue that is separate from the red areas detected by Chandra consists of what is known as dark matter, and which can only be detected directly by gravitational lensing.Credit: ESA/Hubble, NASA, HST Frontier Fields. Acknowledgement: Mathilde Jauzac (Durham University, UK) and Jean-Paul Kneib (École Polytechnique Fédérale de Lausanne, Switzerland).

This image shows the galaxy cluster MCS J0416.1–2403. The blue is dark matter mapped in this study. Image Credit: ESA / Hubble, NASA

The Milky Way measures 100 to 120 thousand light-years across, a distance that defies imagination. But clusters of galaxies, which comprise hundreds to thousands of galaxies swarming under a collective gravitational pull, can span tens of millions of light-years.

These massive clusters are a complex interplay between colliding galaxies and dark matter. They seem impossible to map precisely. But now an international team of astronomers using the NASA/ESA Hubble Space Telescope has done exactly this — precisely mapping a galaxy cluster, dubbed MCS J0416.1–2403, 4.5 billion light-years away.

“Although we’ve known how to map the mass of a cluster using strong lensing for more than twenty years, it’s taken a long time to get telescopes that can make sufficiently deep and sharp observations, and for our models to become sophisticated enough for us to map, in such unprecedented detail, a system as complicated as MCS J0416.1–2403,” said coauthor Jean-Paul Kneib in a press release. [click to continue…]