Hubble Finds Cloudy, Cold Weather Conditions for Mars-Bound Spacecraft
As two NASA spacecraft speed toward a mid-year rendezvous with Mars, astronomers using the Hubble telescope are providing updated planetary weather reports to help plan the missions.
Hubble's new images show that the "Martian invasion" of spacecraft will experience considerably different weather conditions than seen by the last U.S. spacecraft to land on Mars 21 years ago. Martian atmospheric conditions will affect the operation of both the Mars Pathfinder landing on July 4, 1997 and the September 11 arrival of the Mars Global Surveyor, which will map the planet from orbit. These two Hubble snapshots were taken barely three weeks after another Hubble observations of the Red Planet. The differences in the two sets of images are striking, revealing dramatic changes in some local conditions and show overall cloudier and colder conditions than the Viking orbiter encountered two decades ago. (More at Hubble Site)
The Hubble telescope reopened its "eye" on the universe following a successful December 1999 servicing mission by imaging a Sun-like star, dubbed the "Eskimo Nebula" (NGC 2392 and a hefty cluster of galaxies, Abell 2218. (More at Hubble Site)
The Hubble telescope has snapped this remarkable view of a perfectly "edge-on" galaxy, NGC 4013. This new Hubble picture reveals with exquisite detail huge clouds of dust and gas extending along, as well as far above, the galaxy's main disk. NGC 4013 is a spiral galaxy, similar to our Milky Way, lying some 55 million light-years from Earth in the direction of the constellation Ursa Major. Viewed face-on, it would look like a nearly circular pinwheel, but NGC 4013 happens to be seen edge-on from our vantage point. Even at 55 million light-years, the galaxy is larger than Hubble's field of view, and the image shows only a little more than half of the object, albeit with unprecedented detail. (More at Hubble Site)
Burst of Star Formation Drives Bubble in Galaxy's Core
These NASA Hubble Space Telescope snapshots reveal dramatic activities within the core of the galaxy NGC 3079, where a lumpy bubble of hot gas is rising from a cauldron of glowing matter. The picture at left shows the bubble in the center of the galaxy's disk. The structure is more than 3,000 light-years wide and rises 3,500 light-years above the galaxy's disk. The smaller photo at right is a close-up view of the bubble. Astronomers suspect that the bubble is being blown by "winds" (high-speed streams of particles) released during a burst of star formation. Gaseous filaments at the top of the bubble are whirling around in a vortex and are being expelled into space. Eventually, this gas will rain down upon the galaxy's disk where it may collide with gas clouds, compress them, and form a new generation of stars. The two white dots just above the bubble are probably stars in the galaxy. (More at Hubble Site)
This stellar swarm is M80 (NGC 6093), one of the densest of the 147 known globular star clusters in the Milky Way Galaxy. Located about 28,000 light-years from Earth, M80 contains hundreds of thousands of stars, all held together by their mutual gravitational attraction.
Globular clusters are particularly useful for studying stellar evolution, since all of the stars in the cluster have the same age (about 15 billion years), but cover a range of stellar masses. Every star visible in this image is either more highly evolved than, or in a few rare cases more massive than, our own Sun. Especially obvious are the bright red giants, which are stars similar to the Sun in mass that are nearing the ends of their lives. (More at Hubble Site)
This troupe of four galaxies, known as Hickson Compact Group 87 (HCG 87), is performing an intricate dance orchestrated by the mutual gravitational forces acting between them. The dance is a slow, graceful minuet, occurring over a time span of hundreds of millions of years.
This Hubble telescope image reveals complex details in the dust lanes of the group's largest galaxy member (HCG 87a), which is actually disk-shaped, but tilted so that we see it nearly edge-on. Both 87a and its elliptically shaped nearest neighbor (87b) have active galactic nuclei, which are believed to harbor black holes that are consuming gas. A third group member, the nearby spiral galaxy 87c, may be undergoing a burst of active star formation. The three galaxies are so close to each other that gravitational forces disrupt their structure and alter their evolution. (More at Hubble Site)
Bigger, Better Catalog Unveils Half a Billion Celestial Objects
It's a very big universe out there, and an astronomer's work is never done when it comes to simply counting and cataloging the sheer number of stars in the heavens. Completing a seven-year effort at digitizing the entire sky for a second time, astronomers at the Space Telescope Science Institute and the Osservatorio Astronomico di Torino are releasing the Guide Star Catalog II. This new version, which replaces the historic 1989 catalog, provides important information on nearly one-half billion stars - over 20 times as many as the original Guide Star Catalog. (More at Hubble Site)
Looming like a giant flying saucer in our outer solar system, Saturn puts on a show as the planet and its magnificent ring system nod majestically over the course of its 29-year journey around the Sun. These Hubble telescope images, captured from 1996 to 2000, show Saturn's rings open up from just past edge-on to nearly fully open as it moves around the Sun. (More at Hubble Site)
Hint of Planet-Sized Drifters Bewilders Hubble Scientists
Piercing the heart of a globular star cluster, NASA's Hubble Space Telescope uncovered tantalizing clues to what could be a strange and unexpected population of wandering, planet-sized objects. The orbiting observatory detected these bodies in the globular cluster M22 by the way their gravity bends the light from background stars, a phenomenon called microlensing. These microlensing events were unusually brief, indicating that the mass of the the intervening objects could be as little as 80 times that of Earth. Bodies this small have never been detected by microlensing observations. (More at Hubble Site)
The Hubble telescope has caught a cosmic dance between two spiral galaxies. The larger galaxy, NGC 2207, is on the left; the smaller one, IC 2163, is on the right. Their dance has already caused quite a stir. Strong gravitational forces from NGC 2207 have distorted the shape of its smaller dance partner, flinging out stars and gas into long streamers that extend 100,000 light-years toward the right-hand edge of the picture. Eventually this dance will end. Billions of years from now the two galaxies will become one. (More at Hubble Site)
This Hubble telescope image of the Trifid Nebula reveals a stellar nursery being torn apart by radiation from a nearby, massive star. The picture also provides a peek at embryonic stars forming within an ill-fated cloud of dust and gas, which is destined to be eaten away by the glare from the massive neighbor. This stellar activity is a beautiful example of how the life cycles of stars like our Sun are intimately connected with their more powerful siblings. (More at Hubble Site)
Hubble Telescope Reveals Swarm of Glittering Stars in Nearby Galaxy
Peering at a small area within the Large Magellanic Cloud (LMC), the Hubble telescope has provided the deepest color picture ever obtained in this satellite galaxy of the Milky Way. More than 10,000 stars can be seen in this photo, covering a region about 130 light-years wide. The LMC is a small companion galaxy of the Milky Way, visible only from Earth's southern hemisphere. It attracts the attention of modern-day astronomers because, at a distance of only 168,000 light-years, it is one of the nearest galaxies. (More at Hubble Site)
Pictures obtained with the Hubble telescope reveal episodes of star formation that are occurring across the face of the nearby galaxy NGC 4214. Located some 13 million light-years from Earth, NGC 4214 is forming clusters of new stars from its interstellar gas and dust. In the Hubble image, we can see a sequence of steps in the formation and evolution of stars and star clusters. Clouds of glowing gas surrounding bright stellar clusters dominate the picture. (More at Hubble Site)
A star 40 times more massive than the Sun is blowing a giant bubble of material into space. In this colorful picture, the Hubble telescope has captured a glimpse of the expanding bubble, dubbed the Bubble Nebula (NGC 7635). The beefy star [lower center] is embedded in the bright blue bubble. The stellar powerhouse is so hot that it is quickly shedding material into space. The dense gas surrounding the star is shaping the castoff material into a bubble. The bubble's surface is not smooth like a soap bubble's. Its rippled appearance is due to encounters with gases of different thickness. The nebula is 6 light-years wide and is expanding at 4 million miles per hour (7 million kilometers per hour). The nebula is 7,100 light-years from Earth in the constellation Cassiopeia. (More at Hubble Site)
When 19th century astronomer Sir John Herschel spied a swirling cloud of gas with a hole punched through it, he dubbed it the Keyhole Nebula. Now the Hubble telescope has taken a peek at this region, and the resulting image reveals previously unseen details of the Keyhole's mysterious, complex structure. The Keyhole is part of a larger region called the Carina Nebula (NGC 3372), about 8,000 light-years from Earth. (More at Hubble Site)
Hubble Takes a Close-up View of a Reflection Nebula in Orion
Just weeks after NASA astronauts repaired the Hubble Space Telescope in December 1999, the Hubble Heritage Project snapped this picture of NGC 1999, a nebula in the constellation Orion. The Heritage astronomers, in collaboration with scientists in Texas and Ireland, used Hubble's Wide Field Planetary Camera 2 (WFPC2) to obtain the color image. (More at Hubble Site)
The Hubble telescope has spied a giant celestial "eye," known as planetary nebula NGC 6751. The Hubble Heritage Project is releasing this picture to commemorate the Hubble telescope's tenth anniversary. Glowing in the constellation Aquila, the nebula is a cloud of gas ejected several thousand years ago from the hot star visible in its center. Planetary nebulae have nothing to do with planets. They are shells of gas thrown off by Sun-like stars nearing the ends of their lives. The star's loss of its outer, gaseous layers exposes the hot stellar core, whose strong ultraviolet radiation then causes the ejected gas to fluoresce as the planetary nebula. (More at Hubble Site)
Through an extraordinary chance alignment, the Hubble telescope has captured a view of a face-on spiral galaxy lying precisely in front of another larger spiral. The unique pair is called NGC 3314. This line-up provides astronomers with the rare chance to see the dark material within the foreground galaxy, seen only because it is silhouetted against the light from the object behind it. NGC 3314 lies about 140 million light-years from Earth in the direction of the southern hemisphere constellation Hydra. This picture is one of many produced by the Hubble Heritage Program, created 1-1/2 years ago to publicly release some of the best celestial views taken by the telescope's visible-light camera. Now, the International Center of Photography in New York City has rewarded the program for its work with the annual Infinity Award for Applied Photography. (More at Hubble Site)
In the year 1054 A.D., Chinese astronomers were startled by the appearance of a new star, so bright that it was visible in broad daylight for several weeks. Today, the Crab Nebula is visible at the site of that bright star. Located about 6,500 light-years from Earth, the Crab Nebula is the remnant of a star that began its life with about 10 times the mass of our Sun. Its life ended on July 4, 1054 when it exploded as a supernova. In this image, the Hubble telescope has zoomed in on the center of the Crab to reveal its structure with unprecedented detail. (More at Hubble Site)
The Hubble telescope is following dramatic and rapid changes in Jupiter's turbulent atmosphere that will be critical for planning observations for the Galileo space probe when it arrives at the giant planet later this year.
This Hubble image provides a detailed look at a unique cluster of three white, oval-shaped storms that lie southwest [below and to the left] of Jupiter's Great Red Spot [dark oval-shaped object near the picture's right edge]. The appearance of the clouds is considerably different from their appearance only seven months earlier. Hubble shows these features moving closer together as the Great Red Spot is carried westward by the prevailing winds, while the white ovals are swept eastward. (More at Hubble Site)
