The longer a telescope spends looking at a target, the more sensitive the observations become, and the deeper we can look into space. But to get the full picture of what’s happening in the Universe, astronomers also need observations at a range of different wavelengths, requiring different telescopes. These are the key ideas behind the Great Observatories Origins Deep Survey, or GOODS for short.
The GOODS project unites the world’s most advanced observatories, these include ESO’s Very Large Telescope, the NASA/ESA Hubble Space Telescope, the Spitzer Space Telescope, the Chandra X-ray Observatory and many more, each making extremely deep observations of the distant Universe, across the electromagnetic spectrum. By combining their powers and observing the same piece of the sky, the GOODS observatories are giving us a unique view of the formation and evolution of galaxies across cosmic time, and mapping the history of the expansion of the Universe.
Now, this is not the first time that telescopes have been used to give us extremely deep views of the cosmos. For example, the Hubble Deep Field is a very deep image of a small piece of sky in the northern constellation of Ursa Major. This revealed thousands of distant galaxies despite the Continue reading Mapping the History of Space & Time→
This video is modeled in the classic tradition of P.T. Barnum, offering a collection of oddities for your viewing pleasure. So enter the Curiosity Shop for a compilation of facts and beautiful moon images taken by the Cassini spacecraft in orbit around Saturn since 2004, set to Edvard Grieg’s Piano Concerto in A Minor, Op. 16 II. Adagio. This video is produced in honor of the recent Cassini Spacecraft Mission extension through September 2017.
Take a gander at Gigantic Titan to your left. Feel free to ogle bright Enceladus to your right, reflecting close to 100 percent of the light that hits its surface. Don’t be afraid to eyeball Mimas and her craters. That’s what she’s there for! Saturn has the second most moons of planets in the solar system. Second, only to Jupiter.
September 27th, 2010 marked the end of the Cassini Equinox Mission, which was over the last 2 years, and the beginning of the Cassini Solstice Mission. The extension to takes the spacecraft to September 2017, a couple months past Saturn’s Northern summer solstice in May 2017. Cassini has done a great deal to extend our knowledge of Continue reading Curiosity Shop of Saturn’s Moons→
What is the true long-term threat of Near Earth Objects? NASA defines “potentially hazardous” as a Near Earth Object that will pass within .05 AU from Earth and is at least 140 meters in diameter. (http://neo.jpl.nasa.gov/neo/pha.html)
But consider the damage left by a 30-meter object in the famed Siberian impact of 1908:
“Recent scientific studies by meteorite researcher Christopher Chyba have estimated that the Tunguska event may have been caused by the explosion of a stony meteroid about 30 meters in diameter traveling at about 15 km/s. Compare the energy released by such an object with that of an atomic bomb such as those dropped on Japan in World War II.”
The truth is no one really knows how many asteroids this size or larger are out there. According to NASA sources, the population breaks down as follows:
100 meters in diameter: 300,000
500 meters in diameter: 10,000
Over one kilometer in diameter: 500-1,000
The good news is that eight projects are at work to search for them, including NASA’s NEO-Wise space telescope, and more are coming on line soon. The bad news is that fewer than 8,000 of these have been discovered so far.
Recently astronomers used the Suzaku orbiting X-ray observatory, operated jointly by NASA and the Japanese space agency, to discover the largest known reservoir of rare metals in the universe. Suzaku detected the elements chromium and manganese while observing the central region of the Perseus galaxy cluster. The metallic atoms are part of the hot gas, or “intergalactic medium,” that lies between galaxies.
Thumbnail: “The Robot (3) 20102007 Inspired by Hajime Sorayama by Emile Noordeloos.”
Exploding stars, or supernovas, forge the heavy elements. The supernovas also create vast outflows, called superwinds. These galactic gusts transport heavy elements into the intergalactic void.
What is the universe made of? The vast majority of it consists of the wispy cosmic lightweights hydrogen and helium. Everything else on the periodic table contributes only a small fraction of the whole.
Elements heavier than hydrogen and helium are forged in stars, and during their explosive deaths as supernovas.
Type 1a supernovas are nature’s most productive foundries. An old white dwarf star pulls gas off its giant neighbor. The dwarf gains mass until it becomes unstable and blows itself to bits.
The explosion creates vast amounts of heavy elements and blasts them into space.
From ESOCast: An international team of astronomers using ESO’s Very Large Telescope has measured the distance to the most remote galaxy so far. This is the first time that astronomers have been able to confirm that they are observing a galaxy as it was in the era of reionization — when the first generation of brilliant stars was making the young Universe transparent and ending the cosmic Dark Ages.
We are going to find out how a team of astronomers used ESO’s Very Large Telescope, the VLT, to confirm that a galaxy that had previously been spotted in images from the NASA/ESA Hubble Space Telescope is in fact the most distant object that is ever been identified in the Universe.
Studying these first galaxies is extremely difficult; they are very faint and small and by the time their dim light gets to Earth it falls mostly in the infrared part of the spectrum because it has been stretched by the expansion of the Universe.
From the Spitzer Science Center: The gas-giant planet, named upsilon Andromedae b, orbits tightly around its star, with one face perpetually boiling under the star’s heat. It belongs to a class of planets termed hot Jupiters, so called for their scorching temperatures and large, gaseous constitutions.
One might think the hottest part of these planets would be directly under the sun-facing side, but previous observations have shown that their hot spots may be shifted slightly away from this point. Astronomers thought that fierce winds might be pushing hot, gaseous material around.
But the new finding may throw this theory into question. Using Spitzer, an infrared observatory, astronomers found that upsilon Andromedae b’s hot spot is offset by a whopping 80 degrees. Basically, the hot spot is over to the side of the planet instead of directly under the glare of the sun.
“We really didn’t expect to find a hot spot with such a large offset,” said Ian Crossfield, lead author of a new paper about the discovery appearing in an upcoming issue of Astrophysical Journal. “It’s clear that we understand even less about the atmospheric energetics of hot Jupiters than we thought we did.”
From JPL. Comets are important because they represent the leftover bits and pieces from the outer solar system formation process, which took place four and a half billion years ago. As the planets formed, the first thing you got was tiny clumps of dust in the inner solar system, and in the outer system, dust and ice.
The comets are what made the cores of Jupiter, Saturn, Uranus and Neptune. But the planets are so hot that the chemistry changes completely, whereas the comets have remained frozen the entire time so that the chemistry is preserved. Comets are basically made up of a number of different regions; a dirty ice ball, relatively small and black. When it gets near the sun these ices start vaporizing, which forms a atmosphere. And then, when some of these dust particles are blown back away from the sun because of the pressure of sunlight, you form a dust tail and often a gas or ion tail.
Comets and asteroids have always gotten bad press. The dinosaurs checked out 65 million years ago because of an asteroid impact. But what we don’t hear about, is how important these objects are in terms of bringing the building blocks Continue reading Rendezvous with a Comet→
From ESA’s HubbleCast. In early 2009, a team of astronauts visited Hubble to repair the wear and tear of twenty years of operating in a hostile environment — and to install two new instruments, the Cosmic Origins Spectrograph, and Wide Field Camera 3 — better known as WFC3.
Hubble has become famous for its striking visible-light pictures of huge clouds of interstellar dust and gas. But sometimes scientists want to know what’s happening behind, or inside, the cloud of dust. Making infrared observations pulls away the veil and reveals the hidden stars.
Until now, infrared imaging was challenging with Hubble. The Near Infrared Camera and Multi-object Spectrometer, or NICMOS, did allow astronomers to study objects in infrared light in ways not possible from the ground, but it forced them to make a difficult choice. Because its images were small — only about 65 000 pixels in total, similar to a mobile phone screen — NICMOS could produce the sharpest images only if it concentrated on a very narrow field of view. Taking in a wider view came at the cost of losing much of the detail.
From NASA’s James Webb Telescope, feast on this gorgeous, ground-breaking visualization that explores how stars form in dense dusty regions of our galaxy such as the Eagle nebula. With its huge mirror, the James the Webb Space Telescope will be able to see inside these dense clouds of gas and dust. From NASA. Visualizations by Donna Cox and her team at the Advanced Visualization Lab of the National Center for Supercomputing Applications, University of Illinois.
From NASA, here’s a vivid look at the future of our Milky Way in an ultra high-end computer simulation of spiral galaxies colliding. Collisions and mergers are central to galaxy evolution, from the earliest dwarf galaxies that formed to the familiar galaxies we see today. These collisions in action will be targets for the James Webb Telescope. Astronomers hope to understand how the shape, structure and chemical content of galaxies change over the sweep of cosmic history.