For the first time in decades I have been playing a video game.
Growing up, we had a state of the art video game console in the house, an Atari 2600. This machine was impressive… For the late 1970’s. Specifications included color graphics, 160×192 pixel resolution, and monaural sound. My brother and I played for hours, eventually beating some of the joysticks to the point where they required replacement. I mastered Space Invaders, I could play through all of the levels, wrapping back to level 1 for as long as my stamina allowed.
Atari tanks game, circa 1978One of the games bundled with the Atari was Combat, there were four games on the cartridge including a tank game. I look back on that first game, one of the first we played on that console, with a bit of nostalgia. Two tanks maneuvered around a simple obstacle course, with a point awarded for each shot that hit the opponent. The audio was similarly quite simple, a basic growling sound meant to sound like engines and a few sound effects for the shots.
In the intervening decades I have seldom played video games with any great intensity. There was an Apple II space adventure game called Elite that I did play for a while in the 1980’s, but little else.
Astronomers have for the first time spotted four images of a distant exploding star, arranged in a cross-shape pattern by a powerful gravitational lens. In addition to being a unique sighting, the discovery will provide insight into the distribution of dark matter. The findings will appear March 6 in a special issue of the journal Science, celebrating the centenary of Albert Einstein’s Theory of General Relativity.
This image shows the light of a supernova split into four images by a foreground elliptical galaxy embedded in a giant cluster of galaxies. The four images were spotted on Nov. 11, 2014. Credit: NASA/ESATwo teams spent a week analyzing the object’s light, confirming it was the signature of a supernova, then turned to the W. M. Keck Observatory on Mauna Kea, in Hawaii, to gather critical measurements including determining the distance to the supernova’s host galaxy 9.3 billion light-years from Earth.
To explain the unique, four-up projection, the scientists determined a galaxy cluster and one of its massive elliptical members are gravitationally bending and magnifying the light from the supernova behind it, through an effect called gravitational lensing. First predicted by Albert Einstein, this effect is similar to a glass lens bending light to magnify and distort the image of an object behind it. The multiple images, arranged around the massive elliptical galaxy, form an Einstein Cross, a name originally given to a multiple-lensed quasar that appear as a cross.
Although astronomers have discovered dozens of multiply imaged galaxies and quasars, they have never seen a stellar explosion resolved into several images. “It really threw me for a loop when I spotted the four images surrounding the galaxy – it was a complete surprise,” said Patrick Kelly of the University of California, Berkeley, lead author of the paper and a member of the Grism Lens Amplified Survey from Space (GLASS) collaboration. The GLASS group is working with the FrontierSN team to analyze the supernova.
Scientists using the W. M. Keck Observatory and Pan-STARRS1 telescopes on Hawaii have discovered a star that breaks the galactic speed record, traveling with a velocity of about 1,200 kilometers per second or 2.7 million miles per hour. This velocity is so high, the star will escape the gravity of our galaxy. In contrast to the other known unbound stars, the team showed that this compact star was ejected from an extremely tight binary by a thermonuclear supernova explosion. These results will be published in the March 6 issue of Science.
An artist impression of the mass-transfer phase followed by a double-detonation supernova that leads to the ejection of US 708. Credit: ESA/Hubble, NASA, S. GeierStars like the Sun are bound to our Galaxy and orbit its center with moderate velocities. Only a few so-called hypervelocity stars are known to travel with velocities so high that they are unbound, meaning they will not orbit the galaxy, but instead will escape its gravity to wander intergalactic space.
A close encounter with the supermassive black hole at the centre of the Milky Way is typically presumed the most plausible mechanism for kicking these stars out of the galaxy.
A team of astronomers led by Stephan Geier (European Southern Observatory, Garching) observed the known high-velocity star know as US 708 with the Echellette Spectrograph and Imager instrument on the 10-meter, Keck II telescope to measure its distance and velocity along our line of sight. By carefully combining position measurements from digital archives with newer positions measured from images taken during the course of the Pan-STARRS1 survey, they were able to derive the tangential component of the star’s velocity (across our line of sight).
Putting the measurements together, the team determined the star is moving at about 1,200 kilometers per second – much higher than the velocities of previously known stars in the Milky Way galaxy. More importantly, the trajectory of US 708 means the supermassive black hole at the galactic center could not be the source of US 708’s extreme velocity.
A primitive ocean on Mars once held more water than Earth’s Arctic Ocean, according to NASA scientists who measured signatures of water in the planet’s atmosphere using the most powerful telescopes on Earth including the W. M. Keck Observatory in Hawaii. The results are being published in the journal Science on March 6, 2015.
NASA scientists have determined that a primitive ocean on Mars held more water than Earth’s Arctic Ocean and that the Red Planet has lost 87 percent of that water to space. Credit: NASA/GSFCThe young planet would have had enough water to cover the entire surface in a liquid layer about 450 feet (137 meters) deep. More likely, the water would have formed an ocean occupying almost half of Mars’ northern hemisphere, in some regions reaching depths greater than a mile (1.6 kilometers).
“Our study provides a solid estimate of how much water Mars once had, by determining how much water was lost to space,” said Geronimo Villanueva, first author of the paper and scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “With this work, we can better understand the history of water on Mars.”
The new estimate is based on detailed observations of two slightly different forms of water in Mars’ atmosphere. One is the familiar H2O, made with two hydrogens and one oxygen. The other is HDO, a naturally occurring variation in which one hydrogen is replaced by a heavier form, called deuterium.
It snowed much of yesterday and well into the night. The result? Probably about a foot total at the summit, the Mauna Kea rangers report drifts of up to two feet in places. I am scheduled up top tomorrow, maybe some more photos?
A MastCam view peeking through the ice at the Keck 1 dome
It is snowing pretty hard on the summit of Mauna Kea right now. There were a few inches from the previous days, looks like quite a bit more by tomorrow…
Snow falling around the IRTF telescope on the afternoon of March 3, 2015
With the start of March the observatory known as JAC is no more. The Joint Astronomy Center ran two telescopes, the United Kingdom Infrared Telescope (UKIRT) and the James Clerk Maxwell Telescope (JCMT). Both telescopes have been transferred to new management and will continue to pursue science.
You can get more details on Tom Kerr’s blog A Pacific View.
I would also suggest you take a few minutes and enjoy some beautiful time-lapse to celebrate the achievements of the JAC…
