Author: Just Space

The Prague Astronomical Clock : In the center…

The Prague Astronomical Clock : In the center of Prague there’s a clock the size of a building. During the day, crowds gather to watch the show when it chimes in a new hour. The Prague Astronomical Clock’s face is impressively complex, giving not only the expected time with respect to the Sun (solar time), but the time relative to the stars (sidereal time), the times of sunrise and sunset, the time at the equator, the phase of the Moon, and much more. The clock began operation in 1410, and even though much of its inner workings have been modernized several times, original parts remain. Below the clock is a nearly-equal sized, but static, solar calendar. Pictured, the Prague Astronomical Clock was photographed alone during an early morning in 2009 March. The Prague Astronomical Clock and the Old Town Tower behind it are currently being renovated once again, with the clock expected to be restarted in 2018 June. via NASA

Pandora, the Would-Be Perturber : As Cassini h…

Pandora, the Would-Be Perturber : As Cassini hurtled toward its fatal encounter with Saturn, the spacecraft turned to catch this final look at Saturn’s moon Pandora next to the thin line of the F ring. (via NASA)

A Year of Full Moons : Do all full moons loo…

A Year of Full Moons : Do all full moons look the same? No. To see the slight differences, consider this grid of twelve full moons. From upper left to lower right, the images represent every lunation from 2016 November through 2017 October, as imaged from Pakistan. The consecutive full moons are all shown at the same scale, so unlike the famous Moon Illusion, the change in apparent size seen here is real. The change is caused by the variation in lunar distance due to the Moon’s significantly non-circular orbit. The dark notch at the bottom of the full moon of 2017 August is the shadow of the Earth – making this a partial lunar eclipse. Besides the sometimes exaggerated coloring, a subtler change in appearance can also be noticed on close examination, as the Moon seems to wobble slightly from one full moon to the next. This effect, known as libration, is more dramatic and easier to see in this lunation video highlighting all of the ways that the Moon appears to change over a month (moon-th). via NASA

Tests Ensure Astronaut, Ground Crew Safety Bef…

Tests Ensure Astronaut, Ground Crew Safety Before Orion Launches : NASA is performing a series of tests to evaluate how astronauts and ground crew involved in final preparations before Orion missions will quickly get out of the spacecraft, if an emergency were to occur on the pad prior to launch. (via NASA)

A 2017 U1: An Interstellar Visitor : Traveling…

A 2017 U1: An Interstellar Visitor : Traveling at high velocity along an extreme hyperbolic orbit and making a hairpin turn as it swung past the Sun, the now designated A/2017 U1 is the first known small body from interstellar space. A point of light centered in this 5 minute exposure recorded with the William Herschel Telescope in the Canary Islands on October 28, the interstellar visitor is asteroid-like with no signs of cometary activity. Faint background stars appear streaked because the massive 4.2 meter diameter telescope is tracking the rapidly moving A/2017 U1 in the field of view. Astronomer Rob Weryk (IfA) first recognized the moving object in nightly Pan-STARRS sky survey data on October 19. A/2017 is presently outbound, never to return to the Solar System, and already only visible from planet Earth in large optical telescopes. Though an interstellar origin has been established based on its orbit, it is still unknown how long the object could have drifted among the stars of the Milky Way. But its interstellar cruise speed would be about 26 kilometers per second. By comparison humanity’s Voyager 1 spacecraft travels about 17 kilometers per second through interstellar space. via NASA

Revealing What Lies Beneath : This false-color…

Revealing What Lies Beneath : This false-color image demonstrates how use of special filters available on the Curiosity Mars rover’s Mast Camera (Mastcam) can reveal the presence of certain minerals in target rocks. T (via NASA)

NGC 891 vs Abell 347 : Distant galaxies lie be…

NGC 891 vs Abell 347 : Distant galaxies lie beyond a foreground of spiky Milky Way stars in this telescopic field of view. Centered on yellowish star HD 14771, the scene spans about 1 degree on the sky toward the northern constellation Andromeda. At top right is large spiral galaxy NGC 891, 100 thousand light-years across and seen almost exactly edge-on. About 30 million light-years distant, NGC 891 looks a lot like our own Milky Way with a flattened, thin, galactic disk. Its disk and central bulge are cut along the middle by dark, obscuring dust clouds. Scattered toward the lower left are members of galaxy cluster Abell 347. Nearly 240 million light-years away, Abell 347 shows off its own large galaxies in the sharp image. They are similar to NGC 891 in physical size but located almost 8 times farther away, so Abell 347 galaxies have roughly one eighth the apparent size of NGC 891. via NASA

From Hot to Hottest : This sequence of images …

From Hot to Hottest : This sequence of images shows the Sun from its surface to its upper atmosphere all taken at about the same time on Oct. 27, 2017. (via NASA)

Thors Helmet Emission Nebula : This helmet-s…

Thors Helmet Emission Nebula : This helmet-shaped cosmic cloud with wing-like appendages is popularly called Thor’s Helmet. Heroically sized even for a Norse god, Thor’s Helmet spans about 30 light-years across. In fact, the helmet is more like an interstellar bubble, blown as a fast wind – from the bright star near the center of the bubble’s blue-hued region – sweeps through a surrounding molecular cloud. This star, a Wolf-Rayet star, is a massive and extremely hot giant star thought to be in a brief, pre-supernova stage of evolution. Cataloged as NGC 2359, the emission nebula is located about 12,000 light-years away toward the constellation of the Big Dog (Canis Major). The sharp image, made using broadband and narrowband filters, captures striking details of the nebula’s filamentary gas and dust structures. The blue color originates from strong emission from oxygen atoms in the nebula. via NASA

Learning to Walk Before Heading to Space : Can…

Learning to Walk Before Heading to Space : Canadian Space Agency astronaut Jeremy Hansen is suspended over a mock-up of the International Space Station during a microgravity simulation. (via NASA)