Hubble Watched a Pulsating Stellar Relic: This NASA/ESA Hubble Space Telescope image shows the planetary nebula NGC 2452, located in the southern constellation of Puppis. The blue haze across the frame is what remains of a star like our sun after it has depleted all its fuel. When this happens, the core of the star becomes unstable and releases huge numbers of incredibly energetic particles that blow the star's atmosphere away into space. At the center of this blue cloud lies what remains of the nebula's progenitor star. This cool, dim, and extremely dense star is actually a pulsating white dwarf, meaning that its brightness varies over time as gravity causes waves that pulse throughout the small star's body. NGC 2452 was discovered by Sir John Herschel in 1847. He initially defined it as "an object whose nature I cannot make out. It is certainly not a star, nor a close double star [...] I should call it an oblong planetary nebula." To early observers like Herschel with their smaller telescopes, planetary nebulae resembled gaseous planets, and so were named accordingly. The name has stuck, although modern telescopes like Hubble have made it clear that these objects are not planets at all, but the outer layers of dying stars being thrown off into space.
The first Cygnus commercial cargo spacecraft built by Orbital Sciences is seen here attached to the International Space Station's Harmony node. This week, the Cygnus cargo spacecraft that was launched from NASA’s Wallops Flight Facility on Sept.18, will complete its successful maiden cargo mission on Tuesday when it un-berths from the International Space Station and burns up harmlessly in Earth’s atmosphere during re-entry the following day. Orbital Sciences Corp. joins SpaceX as NASA’s second American commercial partner capable of successful resupply missions to the ISS.
A magnetic filament of solar material erupted on the sun in late September, breaking the quiet conditions in a spectacular fashion. The 200,000 mile long filament ripped through the sun's atmosphere, the corona, leaving behind what looks like a canyon of fire. The glowing canyon traces the channel where magnetic fields held the filament aloft before the explosion. In reality, the sun is not made of fire, but of something called plasma: particles so hot that their electrons have boiled off, creating a charged gas that is interwoven with magnetic fields.
These images were captured on Sept. 29-30, 2013, by NASA's Solar Dynamics Observatory, or SDO, which constantly observes the sun in a variety of wavelengths.
> Northern and Southern Aurora Seen from Sept. 30, 2013 CME > NASA Releases Movie of Sun's Canyon of Fire
Different wavelengths help capture different aspect of events in the corona. The red images shown in the movie help highlight plasma at temperatures of 90,000° F and are good for observing filaments as they form and erupt. The yellow images, showing temperatures at 1,000,000° F, are useful for observing material coursing along the sun's magnetic field lines, seen in the movie as an arcade of loops across the area of the eruption. The browner images at the beginning of the movie show material at temperatures of 1,800,000° F, and it is here where the canyon of fire imagery is most obvious. By comparing this with the other colors, one sees that the two swirling ribbons moving farther away from each other are, in fact, the footprints of the giant magnetic field loops, which are growing and expanding as the filament pulls them upward.
Another day, another beautiful view of Mercury's horizon. In this scene, which was acquired looking from the shadows toward the sunlit side of the planet, a 120-km (75 mi.) impact crater stands out near the center. Emanating from this unnamed crater are striking chains of secondary craters, which gouged linear tracks radially away from the crater. While this crater is not especially fresh (its rays have faded into the background), it does appear to have more prominent secondary crater chains than many of its peers.
This image was acquired on Oct. 2, 2013 by the Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS) aboard NASA's MESSENGER spacecraft, as part of the MDIS's limb imaging campaign. Once per week, MDIS captures images of Mercury's limb, with an emphasis on imaging the southern hemisphere limb. These limb images provide information about Mercury's shape and complement measurements of topography made by the Mercury Laser Altimeter (MLA) of Mercury's northern hemisphere.
The MESSENGER spacecraft is the first ever to orbit the planet Mercury, and the spacecraft's seven scientific instruments and radio science investigation are unraveling the history and evolution of the solar system's innermost planet. During the first two years of orbital operations, MESSENGER acquired over 150,000 images and extensive other data sets. MESSENGER is capable of continuing orbital operations until early 2015.
Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
A Ghostly Trio from NASA's Spitzer Space Telescope
In the spirit of Halloween, scientists are releasing a trio of stellar ghosts caught in infrared light by NASA's Spitzer Space Telescope. All three spooky structures, called planetary nebulas, are in fact material ejected from dying stars. As death beckoned, the stars' wispy bits and pieces were blown into outer space.
"Some might call the images haunting," said Joseph Hora of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass., principal investigator of the Spitzer observing program. "We look to the pictures for a sense of the history of the stars’ mass loss, and to learn how they evolved over time."
All stars about the mass of our sun will die similarly ethereal deaths. As sun-like stars grow old, billions of years after their inception, they run out of fuel in their cores and puff up into red, giant stars, aptly named "red giants." The stars eventually cast off their outer layers, which expand away from the star. When ultraviolet light from the core of a dying star energizes the ejected layers, the billowy material glows, bringing their beautiful shapes to light.
These objects in their final death throes, the planetary nebulas, were named erroneously after their resemblance to planets by William Herschel in 1785. They come in an array of shapes, as illustrated by the three highlighted here in infrared images from Spitzer. The ghostly material will linger for only a few thousand years before ultimately fading into the dark night.
Exposed Cranium Nebula
The brain-like orb called PMR 1 has been nicknamed the "Exposed Cranium" nebula by Spitzer scientists. This planetary nebula, located roughly 5,000 light-years away in the Vela constellation, is host to a hot, massive dying star that is rapidly disintegrating, losing its mass. The nebula's insides, which appear mushy and red in this view, are made up primarily of ionized gas, while the outer green shell is cooler, consisting of glowing hydrogen molecules.
Ghost of Jupiter Nebula
The Ghost of Jupiter, also known as NGC 3242, is located roughly 1,400 light-years away in the constellation Hydra. Spitzer's infrared view shows off the cooler outer halo of the dying star, colored here in red. Also evident are concentric rings around the object, the result of material being tossed out periodically during the star's fitful death.
Little Dumbbell Nebula
This planetary nebula, known as NGC 650, or the Little Dumbbell, is about 2,500 light-years from Earth in the Perseus constellation. Unlike the other spherical nebulas, it has a bipolar or butterfly shape due to a "waist," or disk, of thick material, running from lower left to upper right. Fast winds blow material away from the star, above and below this dusty disk. The ghoulish green and red clouds are from glowing hydrogen molecules. The green area is hotter than the red.
A quartet of Saturn's moons, from tiny to huge, surround and are embedded within the planet's rings in this Cassini composition.
Saturn's largest moon, Titan, is in the background of the image, and the moon's north polar hood is clearly visible. See PIA08137 to learn more about that feature on Titan (3,200 miles, or 5,150 kilometers across). Next, the wispy terrain on the trailing hemisphere of Dione (698 miles, or 1,123 kilometers across) can be seen on that moon which appears just above the rings at the center of the image. See PIA10560 and PIA06163 to learn more about Dione's wisps. Saturn's small moon Pandora (50 miles, or 81 kilometers across) orbits beyond the rings on the right of the image. Finally, Pan (17 miles, or 28 kilometers across) can be seen in the Encke Gap of the A ring on the left of the image.
The image was taken in visible blue light with the Cassini spacecraft narrow-angle camera on Sept. 17, 2011. The view was obtained at a distance of approximately 1.3 million miles (2.1 million kilometers) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 27 degrees. Image scale is 8 miles (13 kilometers) per pixel on Dione.
This image provided by NASA shows the Solar Dynamic Observatory's ultra-high-definition view of Venus, black dot at top center, passing in front of the sun on Tuesday, June 5, 2012. The next transit of Venus won't be for another 105 years. (NASA/Solar Dynamic Observatory/AP)
This image provided by NASA shows the image captured by Hinode on June 5, 2012 of the transit of Venus -- the last instance of this rare phenomenon until 2117. Hinode is a joint JAXA/NASA mission to study the connections of the sun's surface magnetism, primarily in and around sunspots. NASA's Marshall Space Flight Center in Huntsville, Ala., manages Hinode. The Smithsonian Astrophysical Observatory in Cambridge, Mass., is the lead U.S. investigator for the X-ray Telescope. (JAXA NASA/AP)
An image released on October 3, 2011 show the Antennae Galaxies (also known as NGC 4038 and 4039) are a pair of distorted colliding spiral galaxies about 70 million light-years away, in the constellation of Corvus (The Crow). This view combines Atacama large milllimetre/submillimetre array (ALMA) observations, made in three different wavelength ranges during the observatory's early testing phase, with visible-light observations from the NASA/ESA Hubble Space Telescope. Most of the ALMA test observations used to create this image were made using only twelve antennas working together -- far fewer than will be used for the first science observations. The first phase of operations at the ALMA complex in Chile's Atacama desert are underway on October 3, 2011 following ten years of construction. Alma's purpose is to study processes occurring a few hundred million years after the formation of the Universe when the first stars began to shine. Alma consists of an array of linked giant antennas on top of the highest plateau in the Atacama desert. AFP PHOTO/ALMA (ESO/NAOJ/NRAO) (Photo credit should read -/AFP/Getty Images)
In this undated image taken by the WISE telescope a massive star is shown plowing through space dust. The result is a brilliant bow shock, seen here as a yellow arc.
This NASA image shows what the Hubble Space Telescope revealed in a majestic disk of stars and dust lanes in the spiral galaxy NGC 2841. A bright cusp of starlight marks the galaxy's center. Spiraling outward are dust lanes that are silhouetted against the population of whitish middle-aged stars. Much younger blue stars trace the spiral arms. NGC 2841 lies 46 million light-years away in the constellation of Ursa Major (The Great Bear). (Hubble Heritage / ESA / NASA)
Central Milky Way Galaxy; image released on Nov. 10, 2009 This is one of the most detailed images to date of the heart of the Milky Way. The galaxy's center is within the white spot near the right edge of the photo. NASA released the image Nov. 10 to mark the 400th anniversary of the telescope. It is a composite of images from three observatories: the Hubble and Spitzer space telescopes and the Chandra X-ray Observatory.
Arp 147 composite black holes -- obtained Feb 15, 2011 This composite image of Arp 147, a pair of interacting galaxies located about 430 million light-years from Earth, shows X-rays from the NASA's Chandra X-ray Observatory (pink) and optical data from the Hubble Space Telescope (red, green, blue) produced by the Space Telescope Science Institute. Arp 147 contains the remnant of a spiral galaxy, right, that collided with the elliptical galaxy on the left. This collision has produced an expanding wave of star formation that shows up as a blue ring containing an abundance of massive young stars. These stars race through their evolution in a few million years or less and explode as supernovas, leaving behind neutron stars and black holes.