Hubble's Largest Galaxy Portrait

A close cropping of spiral galaxy M101 shows an array of stunning details that may be overlooked when viewing the full image. Due to the high sensitivity and fine resolution of Hubble’s Advanced Camera for Surveys, one can clearly see individual dust lanes in the spiral arms as easily as an aerial photo captures rivers flowing through a mountain range here on Earth. Bright, hot regions that are areas of active star formation also dot the spiral arms, akin to ground photos of the bright lights of major cities when photographed at night. Several bright stars appear in this small section of M101 (also known as the Pinwheel Galaxy). They are in our own galaxy, superimposed in the line of sight and appear much brighter than the stars within M101 because they are so much closer. So too, a background spiral galaxy, millions of light-years behind M101, appears between two spiral arms. The bright nucleus of M101 just off to the upper left appears brighter and redder than the rest of the galaxy seen in the image. Stars near the halo that surround the nucleus are older and redder compared to the blue, young, hot stars that delineate the spiral arms and populate the metropolitan-style star-forming regions. This image, a portion of the full M101 Hubble mosaic, contains only Hubble data from blue, green and infrared filters taken in November 2002.

Backpacking in Space

Mission Specialist Bruce McCandless II ventured further away from the confines and safety of his ship than any previous astronaut ever has. This space first was made possible by the Manned Manuevering Unit or MMU, a nitrogen jet propelled backpack. After a series of test maneuvers inside and above Challenger’s payload bay, McCandless went “free-flying” to a distance of 320 feet away from the Orbiter. The MMU is controled by joy sticks positioned at the end of the arm rests. Moving the joy sticks left or right or by pulling them fires nitrogen jet thrusters propelling McCandless in any direction he chooses. A still camera is mounted on the upper right portion of the MMU. This stunning view shows McCandless with the MMU out there amongst the black and blue of Earth and space.

The Launch of Space Shuttle Endeavour

Marsh driftwood and Florida shrubbery frame the liftoff phase of the Space Shuttle Endeavour as it begins theSTS-69 mission. Liftoff from Launch Pad 39A occurred at 11:09:00:52 a.m. (EDT), September 7, 1995. The crew of five NASA astronauts is embarking on an 11-day multifaceted mission featuring two free-flying scientific research spacecraft, a spacewalk and a host of experiments in both the cargo bay and the middeck. Onboard were astronauts David M. Walker, Kenneth D. Cockrell, James S. Voss, James H. Newman and Michael L. Gernhardt.

Bode's Galaxy

This beautiful galaxy is tilted at an oblique angle on to our line of sight, giving a “birds-eye view” of the spiral structure. The galaxy is similar to our Milky Way, but our favorable view provides a better picture of the typical architecture of spiral galaxies. M81 may be undergoing a surge of star formation along the spiral arms due to a close encounter it may have had with its nearby spiral galaxy NGC 3077 and a nearby starburst galaxy (M82) about 300 million years ago. M81 is one of the brightest galaxies that can be seen from the Earth. It is high in the northern sky in the circumpolar constellation Ursa Major, the Great Bear. At an apparent magnitude of 6.8 it is just at the limit of naked-eye visibility. The galaxy’s angular size is about the same as that of the Full Moon. This image combines data from the Hubble Space Telescope, the Spitzer Space Telescope, and the Galaxy Evolution Explorer (GALEX) missions. The GALEX ultraviolet data were from the far-UV portion of the spectrum (135 to 175 nanometers). The Spitzer infrared data were taken with the IRAC 4 detector (8 microns). The Hubble data were taken at the blue portion of the spectrum.

Pinwheel Galaxy

Looking like a child’s pinwheel ready to be set a spinning by a gentle breeze, this dramatic spiral galaxy is one of the latest viewed by NASA’s Hubble Space Telescope. Stunning details of the face-on spiral galaxy, cataloged as NGC 1309, are captured in this color image. Recent observations of the galaxy taken in visible and infrared light come together in a colorful depiction of many of the galaxy’s features. Bright blue areas of star formation pepper the spiral arms, while ruddy dust lanes follow the spiral structure into a yellowish central nucleus of older-population stars. The image is complemented by myriad far-off background galaxies. However, this galaxy image is more than just a pretty picture. It is helping astronomers to more accurately measure the expansion rate of the universe. NGC 1309 was home to supernova SN 2002fk, whose light reached Earth in September 2002. This supernova event, known as a Type Ia, resulted from a white dwarf star accreting matter from its companion in a binary star system. When the white dwarf collected enough mass and was no longer able to support itself, the star detonated, becoming the brightest object in the galaxy for several weeks. Nearby Type Ia supernovae like SN 2002fk inNGC 1309 are used by astronomers to calibrate distance measures in the universe. By comparing nearby Type Ia supernovae to more distant ones, they can determine not only that the universe is expanding, but that this expansion is accelerating. However, this method only works if the distance to the host galaxies is known extremely well. That’s where the Hubble Telescope comes into play. Since NGC 1309 is relatively close to us, the high resolution of Hubble’s Advanced Camera for Surveys can help accurately determine the distance to the galaxy by looking at the light output of a particular type of variable star called a Cepheid variable. Cepheids are well studied in our own galaxy, and vary regularly in brightness at a rate that is directly related to their total intrinsic brightness. By comparing their variation rate with how bright they appear, astronomers can deduce their distance. In this way, the Cepheids in NGC 1309 allow astronomers to accurately measure the distance toNGC 1309, and thus to SN 2002fk. The expansion of the universe was discovered by Edwin Hubble, the Hubble Space Telescope’s namesake, nearly a century ago, but the accelerating expansion is a recent discovery which has interesting consequences for cosmological models. These Hubble images were taken in August and September 2005. NGC 1309 resides 100 million light-years (30 Megaparsecs) from Earth. It is one of about 200 galaxies that make up the Eridanus group of galaxies.

Orion Nebula

A new image from NASA’s Spitzer and Hubble Space Telescopes looks more like an abstract painting than a cosmic snapshot. The magnificent masterpiece shows the Orion nebula in an explosion of infrared, ultraviolet and visible-light colors. It was “painted” by hundreds of baby stars on a canvas of gas and dust, with intense ultraviolet light and strong stellar winds as brushes. At the heart of the artwork is a set of four monstrously massive stars, collectively called the Trapezium. These behemoths are approximately 100,000 times brighter than our sun. Their community can be identified as the yellow smudge near the center of the composite. The swirls of green were revealed by Hubble’s ultraviolet and visible-light detectors. They are hydrogen and sulfur gases heated by intense ultraviolet radiation from the Trapezium’s stars. Wisps of red, also detected by Spitzer, indicate infrared light from illuminated clouds containing carbon-rich molecules called polycyclic aromatic hydrocarbons. On Earth, polycyclic aromatic hydrocarbons are found on burnt toast and in automobile exhaust. Additional stars in Orion are sprinkled throughout the image in a rainbow of colors. Spitzer exposed infant stars deeply embedded in a cocoon of dust and gas (orange-yellow dots). Hubble found less embedded stars (specks of green) and stars in the foreground (blue). Stellar winds from clusters of newborn stars scattered throughout the cloud etched all of the well-defined ridges and cavities. Located 1,500 light-years away from Earth, the Orion nebula is the brightest star in the sword of the hunter constellation. The cosmic cloud is also our closest massive star-formation factory, and astronomers suspect that it contains about 1,000 young stars. The Orion constellation can be seen in the fall and winter night skies from northern latitudes. The constellation’s nebula is invisible to the unaided eye, but can be resolved with binoculars or small telescopes.

Cigar Galaxy

Click to see the Cigar Galaxy in high resolution.

NASA’s Spitzer, Hubble, and Chandra space observatories teamed up to create this multi-wavelength, false-colored view of the M82 galaxy. X-ray data recorded by Chandra appears in blue; infrared light recorded by Spitzer appears in red; Hubble’s observations of hydrogen emission appear in orange, and the bluest visible light appears in yellow-green.

First Spacewalk Ever

Click to view the first space walk in high resolution.

Astronaut Edward H. White II, pilot of the Gemini-Titan 4 flight, floats in space while performing America’s first spacewalk on June 3, 1965. White spent 23 minutes maneuvering around his spacecraft as Jim McDivitt remained inside the spacecraft. White is attached to the spacecraft by a 25-ft. umbilical line and a 23-ft. tether line, both wrapped in gold tape to form one cord. In his right hand White carries a Hand-Held Self Maneuvering Unit (HHSMU), which he used to help move him around the weightless environment of space. The visor of his helmet is gold plated to protect him from the unfiltered rays of the sun.

Mexican Hat in the Sky: Sombrero Galaxy

Click for high resolution Sombrero Galaxy image.

NASA’s Spitzer and Hubble Space Telescopes joined forces to create this striking composite image of one of the most popular sights in the universe. Messier 104 is commonly known as the Sombrero galaxy because in visible light, it resembles the broad-brimmed Mexican hat. However, in Spitzer’s striking infrared view, the galaxy looks more like a “bull’s eye.” In Hubble’s visible light image, only the near rim of dust can be clearly seen in silhouette. Recent observations using Spitzer’s infrared array camera uncovered the bright, smooth ring of dust circling the galaxy, seen in red. Spitzer’s infrared view of the starlight, piercing through the obscuring dust, is easily seen, along with the bulge of stars and an otherwise hidden disk of stars within the dust ring. Spitzer’s full view shows the disk is warped, which is often the result of a gravitational encounter with another galaxy, and clumpy areas spotted in the far edges of the ring indicate young star-forming regions. The Sombrero galaxy is located some 28 million light-years away. Viewed from Earth, it is just six degrees south of its equatorial plane. Spitzer detected infrared emission not only from the ring, but from the center of the galaxy too, where there is a huge black hole, believed to be a billion times more massive than our Sun.

Credit: R. Kennicutt (Steward Obs.) et al., SSC, JPL, Caltech, NASA