2001 February 13
NEAR Spacecraft Survives Landing on Asteroid Eros
Credit: NEAR Project, JHU APL, NASA
Yesterday NEAR-Shoemaker became the first spacecraft to land on an asteroid and send signals back from its surface. Since the robot spacecraft was not designed for such a contingency, the success of the landing on asteroid 433 Eros was not assured. Shown above is the last picture taken by NEAR-Shoemaker before its touchdown. The streaking on the lower part of the image was caused by the loss of telemetry as the satellite impacted the surface. The image was taken 130 meters above the surface and spans 6 meters across. Rocks as small as a human hand are visible. As engineers continue to try to communicate with the beached car-sized spacecraft, scientists will work to understand features visible in the highest resolution photographs ever taken of an asteroid.
NEAR Spacecraft Survives Landing on Asteroid Eros
Credit: NEAR Project, JHU APL, NASA
Yesterday NEAR-Shoemaker became the first spacecraft to land on an asteroid and send signals back from its surface. Since the robot spacecraft was not designed for such a contingency, the success of the landing on asteroid 433 Eros was not assured. Shown above is the last picture taken by NEAR-Shoemaker before its touchdown. The streaking on the lower part of the image was caused by the loss of telemetry as the satellite impacted the surface. The image was taken 130 meters above the surface and spans 6 meters across. Rocks as small as a human hand are visible. As engineers continue to try to communicate with the beached car-sized spacecraft, scientists will work to understand features visible in the highest resolution photographs ever taken of an asteroid.
2001 February 14
The Rosette Nebula
Credit & Copyright: Robert Gendler
Would the Rosette Nebula by any other name look as sweet? The bland New General Catalog designation of NGC 2237 doesn't appear to diminish the appearance of the this flowery emission nebula. Inside the nebula lies an open cluster of bright young stars designated NGC 2244. These stars formed about four million years ago from the nebular material and their stellar winds are clearing a hole in the nebula's center, insulated by a layer of dust and hot gas. Ultraviolet light from the hot cluster stars causes the surrounding nebula to glow. The Rosette Nebula spans about 100 light-years across, lies about 5000 light-years away, and can be seen with a small telescope towards the constellation of Monoceros.
The Rosette Nebula
Credit & Copyright: Robert Gendler
Would the Rosette Nebula by any other name look as sweet? The bland New General Catalog designation of NGC 2237 doesn't appear to diminish the appearance of the this flowery emission nebula. Inside the nebula lies an open cluster of bright young stars designated NGC 2244. These stars formed about four million years ago from the nebular material and their stellar winds are clearing a hole in the nebula's center, insulated by a layer of dust and hot gas. Ultraviolet light from the hot cluster stars causes the surrounding nebula to glow. The Rosette Nebula spans about 100 light-years across, lies about 5000 light-years away, and can be seen with a small telescope towards the constellation of Monoceros.
2001 February 15
Jupiter Unpeeled
Credit: Cassini Imaging Team, Cassini Project, NASA
Slice Jupiter from pole to pole, peel back its outer layers of clouds, stretch them onto a flat surface ... and for all your trouble you'd end up with something that looks a lot like this. Scrolling right will reveal the full picture, a color mosaic of Jupiter from the Cassini spacecraft. The mosaic is actually a single frame from a fourteen frame movie constructed from image data recorded by Cassini during its leisurely flyby of the solar system's largest planet late last year. The engaging movie approximates Jupiter's cloud motions over 24 jovian rotations. To make it, a series of observations covering Jupiter's complete circumference 60 degrees north and south of the equator were combined in an animated cylindrical projection map of the planet. As in the familiar rectangular-shaped wall maps of the Earth's surface, the relative sizes and shapes of features are correct near the equator but become progressively more distorted approaching the polar regions. In the Cassini movie, which also features guest appearances by moons Io and Europa, the smallest cloud structures visible at the equator are about 600 kilometers across. (Note: Downloading a large gif or quicktime version of the movie may take 15 minutes or longer.)
Jupiter Unpeeled
Credit: Cassini Imaging Team, Cassini Project, NASA
Slice Jupiter from pole to pole, peel back its outer layers of clouds, stretch them onto a flat surface ... and for all your trouble you'd end up with something that looks a lot like this. Scrolling right will reveal the full picture, a color mosaic of Jupiter from the Cassini spacecraft. The mosaic is actually a single frame from a fourteen frame movie constructed from image data recorded by Cassini during its leisurely flyby of the solar system's largest planet late last year. The engaging movie approximates Jupiter's cloud motions over 24 jovian rotations. To make it, a series of observations covering Jupiter's complete circumference 60 degrees north and south of the equator were combined in an animated cylindrical projection map of the planet. As in the familiar rectangular-shaped wall maps of the Earth's surface, the relative sizes and shapes of features are correct near the equator but become progressively more distorted approaching the polar regions. In the Cassini movie, which also features guest appearances by moons Io and Europa, the smallest cloud structures visible at the equator are about 600 kilometers across. (Note: Downloading a large gif or quicktime version of the movie may take 15 minutes or longer.)
2001 February 16
Star Forming Region Hubble-X
Credit: C. R. O'Dell (Vanderbilt Univ.) et al., Hubble Heritage Team, NASA
In nearby galaxy NGC 6822, this glowing emission nebula complex surrounds bright, massive, newborn stars. A mere 4 million years young, these stars condensed from the galaxy's interstellar gas and dust clouds. The nebular glow is powered by the bright stars' intense ultraviolet radiation while its shape is sculpted by the interaction of stellar winds and radiation with the immense interstellar clouds themselves. Cataloged as Hubble-X, many skygazers find the appearance of this extragalactic star forming region reminiscent of the most famous stellar nursery in our own galaxy, the Orion Nebula. Hubble-X is intrinsically much brighter than Orion though, and at a distance of 1.6 million light-years it is about 1,000 times farther away. Hubble-X is also about 100 light-years across compared to 10 light-years for the Orion Nebula. Why is it called Hubble-X? X is the Roman numeral 10, this nebula's designation in a catalog of similar objects for galaxy NGC 6822.
Star Forming Region Hubble-X
Credit: C. R. O'Dell (Vanderbilt Univ.) et al., Hubble Heritage Team, NASA
In nearby galaxy NGC 6822, this glowing emission nebula complex surrounds bright, massive, newborn stars. A mere 4 million years young, these stars condensed from the galaxy's interstellar gas and dust clouds. The nebular glow is powered by the bright stars' intense ultraviolet radiation while its shape is sculpted by the interaction of stellar winds and radiation with the immense interstellar clouds themselves. Cataloged as Hubble-X, many skygazers find the appearance of this extragalactic star forming region reminiscent of the most famous stellar nursery in our own galaxy, the Orion Nebula. Hubble-X is intrinsically much brighter than Orion though, and at a distance of 1.6 million light-years it is about 1,000 times farther away. Hubble-X is also about 100 light-years across compared to 10 light-years for the Orion Nebula. Why is it called Hubble-X? X is the Roman numeral 10, this nebula's designation in a catalog of similar objects for galaxy NGC 6822.
2001 February 17
Happy Birthday Jules Verne
Credit: Apollo 9, NASA
One hundred seventy-three years ago on February 8th, Jules Verne was born in Nantes, France. Inspired by a lifelong fascination with machines, Verne wrote visionary works about "Extraordinary Voyages" including such terrestrial travels as Around the World in 80 Days, Journey to the Centre of the Earth, and Twenty Thousand Leagues Under the Sea. In 1865 he published the story of three adventurers who undertook a journey From the Earth to the Moon. Verne's characters rode a "projectile-vehicle" fired from a huge cannon constructed in Florida, USA. Does that sound vaguely familiar? A century later, the Saturn V rocket and NASA's Apollo program finally turned this work of fiction into fact, propelling adventuresome trios on what was perhaps Verne's most extraordinary voyage. This stirring floodlit view shows the Apollo 9 space-vehicle atop its Saturn V. Launched from a spaceport in Florida in 1969, the Apollo 9 crew were the first to test all lunar landing hardware in space.
Happy Birthday Jules Verne
Credit: Apollo 9, NASA
One hundred seventy-three years ago on February 8th, Jules Verne was born in Nantes, France. Inspired by a lifelong fascination with machines, Verne wrote visionary works about "Extraordinary Voyages" including such terrestrial travels as Around the World in 80 Days, Journey to the Centre of the Earth, and Twenty Thousand Leagues Under the Sea. In 1865 he published the story of three adventurers who undertook a journey From the Earth to the Moon. Verne's characters rode a "projectile-vehicle" fired from a huge cannon constructed in Florida, USA. Does that sound vaguely familiar? A century later, the Saturn V rocket and NASA's Apollo program finally turned this work of fiction into fact, propelling adventuresome trios on what was perhaps Verne's most extraordinary voyage. This stirring floodlit view shows the Apollo 9 space-vehicle atop its Saturn V. Launched from a spaceport in Florida in 1969, the Apollo 9 crew were the first to test all lunar landing hardware in space.
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2001 February 18
Lunation
Credit: Ant�nio Cidad�o
Our Moon's appearance changes nightly. This slow-loading time-lapse sequence shows what our Moon looks like during a lunation, a complete lunar cycle. As the Moon orbits the Earth, the half illuminated by the Sun first becomes increasingly visible, then decreasingly visible. The Moon always keeps the same face toward the Earth. The Moon's apparent size changes slightly, though, and a slight wobble called a libration is discernable as it progresses along its elliptical orbit. During the cycle, sunlight reflects from the Moon at different angles, and so illuminates different features differently. A full lunation takes about 29.5 days, just under a month (moon-th).
Lunation
Credit: Ant�nio Cidad�o
Our Moon's appearance changes nightly. This slow-loading time-lapse sequence shows what our Moon looks like during a lunation, a complete lunar cycle. As the Moon orbits the Earth, the half illuminated by the Sun first becomes increasingly visible, then decreasingly visible. The Moon always keeps the same face toward the Earth. The Moon's apparent size changes slightly, though, and a slight wobble called a libration is discernable as it progresses along its elliptical orbit. During the cycle, sunlight reflects from the Moon at different angles, and so illuminates different features differently. A full lunation takes about 29.5 days, just under a month (moon-th).
2001 February 19
Shuttle Plume Shadow Points to Moon
Credit: NASA
Why would the shadow of a space shuttle launch plume point toward the Moon? Two weeks ago during the launch of Atlantis, the Sun, Earth, Moon, and rocket were all properly aligned for this photogenic coincidence. First, for the space shuttle's plume to cast a long shadow, the time of day must be either near sunrise or sunset. Next, just at sunset, the shadow is the longest and extends all the way to the horizon. Finally, during a Full Moon, the Sun and Moon are on opposite sides of the sky. Just after sunset, for example, the Sun is slightly below the horizon, and, in the other direction, the Moon is slightly above the horizon. Therefore, as Atlantis blasted off, just after sunset, its shadow projected away from the Sun toward the opposite horizon, where the Full Moon just happened to be.
Shuttle Plume Shadow Points to Moon
Credit: NASA
Why would the shadow of a space shuttle launch plume point toward the Moon? Two weeks ago during the launch of Atlantis, the Sun, Earth, Moon, and rocket were all properly aligned for this photogenic coincidence. First, for the space shuttle's plume to cast a long shadow, the time of day must be either near sunrise or sunset. Next, just at sunset, the shadow is the longest and extends all the way to the horizon. Finally, during a Full Moon, the Sun and Moon are on opposite sides of the sky. Just after sunset, for example, the Sun is slightly below the horizon, and, in the other direction, the Moon is slightly above the horizon. Therefore, as Atlantis blasted off, just after sunset, its shadow projected away from the Sun toward the opposite horizon, where the Full Moon just happened to be.
2001 February 20
Star Forming Region S106
Credit & Copyright: CISCO, Subaru 8.3-m Telescope, NAOJ
Massive star IRS4 is beginning to spread its wings. Born only about 100,000 years ago, material streaming out from this newborn star has formed the nebula dubbed Sharpless 106 Nebula (S106), pictured above. A large disk of dust and gas orbiting Infrared Source 4 (IRS4), visible in dark red near the image center, gives the nebula an hourglass shape. S106 gas near IRS4 acts as an emission nebula as it emits light after being ionized, while dust far from IRS4 reflects light from the central star and so acts as a reflection nebula. Detailed inspection of this representative color infrared image has revealed hundreds of low-mass brown dwarf stars lurking in the nebula's gas. S106 spans about 2 light-years and lies about 2000 light-years away toward the constellation of Cygnus.
Star Forming Region S106
Credit & Copyright: CISCO, Subaru 8.3-m Telescope, NAOJ
Massive star IRS4 is beginning to spread its wings. Born only about 100,000 years ago, material streaming out from this newborn star has formed the nebula dubbed Sharpless 106 Nebula (S106), pictured above. A large disk of dust and gas orbiting Infrared Source 4 (IRS4), visible in dark red near the image center, gives the nebula an hourglass shape. S106 gas near IRS4 acts as an emission nebula as it emits light after being ionized, while dust far from IRS4 reflects light from the central star and so acts as a reflection nebula. Detailed inspection of this representative color infrared image has revealed hundreds of low-mass brown dwarf stars lurking in the nebula's gas. S106 spans about 2 light-years and lies about 2000 light-years away toward the constellation of Cygnus.
2001 February 21
A Sonic Boom
Credit: Ensign John Gay, USS Constellation, US Navy
Many people have heard a sonic boom, but few have seen one. When an airplane travels at a speed faster than sound, density waves of sound emitted by the plane cannot precede the plane, and so accumulate in a cone behind the plane. When this shock wave passes, a listener hears all at once the sound emitted over a longer period: a sonic boom. As a plane accelerates to just break the sound barrier, however, an unusual cloud might form. The origin of this cloud is still debated. A leading theory is that a drop in air pressure at the plane described by the Prandtl-Glauert Singularity occurs so that moist air condenses there to form water droplets. Above, an F/A-18 Hornet was photographed just as it broke the sound barrier. Large meteors and the space shuttle frequently produce audible sonic booms before they are slowed below sound speed by the Earth's atmosphere.
A Sonic Boom
Credit: Ensign John Gay, USS Constellation, US Navy
Many people have heard a sonic boom, but few have seen one. When an airplane travels at a speed faster than sound, density waves of sound emitted by the plane cannot precede the plane, and so accumulate in a cone behind the plane. When this shock wave passes, a listener hears all at once the sound emitted over a longer period: a sonic boom. As a plane accelerates to just break the sound barrier, however, an unusual cloud might form. The origin of this cloud is still debated. A leading theory is that a drop in air pressure at the plane described by the Prandtl-Glauert Singularity occurs so that moist air condenses there to form water droplets. Above, an F/A-18 Hornet was photographed just as it broke the sound barrier. Large meteors and the space shuttle frequently produce audible sonic booms before they are slowed below sound speed by the Earth's atmosphere.
2001 February 22
3C294: Distant X-Ray Galaxy Cluster
Credit: A. Fabian (IoA Cambridge) et al., NASA
Large clusters of galaxies are the most massive objects in the universe. Astronomers now realize that a hallmark of these cosmic behemoths are gas clouds with temperatures of tens of millions of degrees that pervade the clusters and radiate strongly in x-rays. This Chandra Observatory image centered on a radio galaxy cataloged as 3C294 indeed reveals the telltale hot x-ray gas in an hourglass shaped region surrounding the dominant galaxy and shows the presence of a massive galaxy cluster in the distant universe. Here the picture is color-coded by x-ray energy, red for low, green for medium, and blue for high energy x-rays. The cluster associated with 3C294 is 10 billion light-years away making it the most distant x-ray galaxy cluster ever detected. Objects at that extreme distance existed when the universe was young, a mere 20 percent of its present age. Impressively, this observation demonstrates that even at those early times massive clusters of galaxies were already present.
3C294: Distant X-Ray Galaxy Cluster
Credit: A. Fabian (IoA Cambridge) et al., NASA
Large clusters of galaxies are the most massive objects in the universe. Astronomers now realize that a hallmark of these cosmic behemoths are gas clouds with temperatures of tens of millions of degrees that pervade the clusters and radiate strongly in x-rays. This Chandra Observatory image centered on a radio galaxy cataloged as 3C294 indeed reveals the telltale hot x-ray gas in an hourglass shaped region surrounding the dominant galaxy and shows the presence of a massive galaxy cluster in the distant universe. Here the picture is color-coded by x-ray energy, red for low, green for medium, and blue for high energy x-rays. The cluster associated with 3C294 is 10 billion light-years away making it the most distant x-ray galaxy cluster ever detected. Objects at that extreme distance existed when the universe was young, a mere 20 percent of its present age. Impressively, this observation demonstrates that even at those early times massive clusters of galaxies were already present.
2001 February 23
M55: Color Magnitude Diagram
B.J. Mochejska, J. Kaluzny (CAMK), 1m Swope Telescope
This color "picture" of globular star cluster M55 may not look like any star cluster you've ever seen. Still, it shows a most fundamental view for students of stellar astronomy. In the picture, a Color Magnitude Diagram (CMD), M55's individual stars are represented as dots whose color indicates relative temperature, red (cool) to blue (hot). Position in the CMD does not correspond to a star's location in the sky, though. Instead, it corresponds to a measured astronomical color, (B-V color) read off the bottom scale, and a brightness in magnitudes (M) on the left hand scale. The temperature for each star can also be found by reading the equivalent scale at the top, where the Sun would have a temperature of 6,000 kelvins (K). Brightness relative to the Sun's luminosity (Sun = 1) is given on the scale at the right. The globular cluster stars clearly fall into distinct groups dramatically visible in this CMD. The broad swath extending diagonally from the lower right is the cluster's main sequence. A sharp turn toward the upper right hand corner follows the red giant branch while the blue giants are found grouped in the upper left. M55's stars were formed at the same time and at first were all located along the main sequence by mass, lower mass stars at the lower right. Over time, higher mass stars have evolved off the main sequence into red, then blue giants and beyond. The exact position of the sharp turn-off from the main sequence to the red giant branch measures the cluster's age.
M55: Color Magnitude Diagram
B.J. Mochejska, J. Kaluzny (CAMK), 1m Swope Telescope
This color "picture" of globular star cluster M55 may not look like any star cluster you've ever seen. Still, it shows a most fundamental view for students of stellar astronomy. In the picture, a Color Magnitude Diagram (CMD), M55's individual stars are represented as dots whose color indicates relative temperature, red (cool) to blue (hot). Position in the CMD does not correspond to a star's location in the sky, though. Instead, it corresponds to a measured astronomical color, (B-V color) read off the bottom scale, and a brightness in magnitudes (M) on the left hand scale. The temperature for each star can also be found by reading the equivalent scale at the top, where the Sun would have a temperature of 6,000 kelvins (K). Brightness relative to the Sun's luminosity (Sun = 1) is given on the scale at the right. The globular cluster stars clearly fall into distinct groups dramatically visible in this CMD. The broad swath extending diagonally from the lower right is the cluster's main sequence. A sharp turn toward the upper right hand corner follows the red giant branch while the blue giants are found grouped in the upper left. M55's stars were formed at the same time and at first were all located along the main sequence by mass, lower mass stars at the lower right. Over time, higher mass stars have evolved off the main sequence into red, then blue giants and beyond. The exact position of the sharp turn-off from the main sequence to the red giant branch measures the cluster's age.
2001 February 24
Infrared Horsehead
ESA/ISO, ISOCAM Team and L. Nordh (Stockholm Observatory) et al.
This famous cosmic dust cloud was imaged in infrared light by the European Space Agency's Infrared Space Observatory (ISO) satellite. The false-color picture shows the bright infrared emission from dust and molecular gas in part of the Orion star forming region surrounding the Horsehead Nebula. In visible light, the horsehead-shaped dust cloud looks dark against a background of bright glowing gas. But in this image, the interstellar infrared glow engulfs much of the horse's head. Just above and to the right of center, only the top remains crowned by a bright, newborn star. The very bright object at the lower left is the reflection nebula NGC 2023, a dense concentration of interstellar gas and dust grains also associated with newly formed stars.
Infrared Horsehead
ESA/ISO, ISOCAM Team and L. Nordh (Stockholm Observatory) et al.
This famous cosmic dust cloud was imaged in infrared light by the European Space Agency's Infrared Space Observatory (ISO) satellite. The false-color picture shows the bright infrared emission from dust and molecular gas in part of the Orion star forming region surrounding the Horsehead Nebula. In visible light, the horsehead-shaped dust cloud looks dark against a background of bright glowing gas. But in this image, the interstellar infrared glow engulfs much of the horse's head. Just above and to the right of center, only the top remains crowned by a bright, newborn star. The very bright object at the lower left is the reflection nebula NGC 2023, a dense concentration of interstellar gas and dust grains also associated with newly formed stars.
2001 February 25
The Sudbury Neutrino Detector
Credit: A. B. McDonald (Queen's University) et al., The Sudbury Neutrino Observatory Institute
Two thousand meters below the ground, a giant sphere has begun to detect nearly invisible particles. These particles, neutrinos, are extremely abundant in the universe but usually go right through just about everything. By stocking this 12-meter sphere with an unusual type of heavy water and surrounding it with light detectors, astrophysicists hope to catch the occasional collision. Since the Sudbury Neutrino Observatory (SNO) is sensitive to all types of neutrinos, future results might hold clues to how much neutrinos change types on the fly, how our own Sun emits neutrinos, and even how important neutrinos are to the composition of the entire universe.
The Sudbury Neutrino Detector
Credit: A. B. McDonald (Queen's University) et al., The Sudbury Neutrino Observatory Institute
Two thousand meters below the ground, a giant sphere has begun to detect nearly invisible particles. These particles, neutrinos, are extremely abundant in the universe but usually go right through just about everything. By stocking this 12-meter sphere with an unusual type of heavy water and surrounding it with light detectors, astrophysicists hope to catch the occasional collision. Since the Sudbury Neutrino Observatory (SNO) is sensitive to all types of neutrinos, future results might hold clues to how much neutrinos change types on the fly, how our own Sun emits neutrinos, and even how important neutrinos are to the composition of the entire universe.
2001 February 26
Sand Dunes on Mars
Credit: Malin Space Science Systems, MGS, JPL, NASA
Sand dunes on Mars can appear exotic. The dark dunes above might be compared to shark's teeth or chocolate confections. In reality, they arise from the complex relationship between the sandy surface and high winds on Mars. These particular dunes are located in Proctor Crater, a 170 kilometer wide crater first seen to house sand dunes by Mariner 9 more than 25 years ago. The above picture was taken by Mars Global Surveyor (MGS), a robot spacecraft currently in orbit around Mars. MGS has recently completed a primary goal of taking and transmitting detailed survey images of the red planet over an entire Martian year (669 Earth days). MGS will now be deployed to study particularly interesting regions of Mars in more detail.
Sand Dunes on Mars
Credit: Malin Space Science Systems, MGS, JPL, NASA
Sand dunes on Mars can appear exotic. The dark dunes above might be compared to shark's teeth or chocolate confections. In reality, they arise from the complex relationship between the sandy surface and high winds on Mars. These particular dunes are located in Proctor Crater, a 170 kilometer wide crater first seen to house sand dunes by Mariner 9 more than 25 years ago. The above picture was taken by Mars Global Surveyor (MGS), a robot spacecraft currently in orbit around Mars. MGS has recently completed a primary goal of taking and transmitting detailed survey images of the red planet over an entire Martian year (669 Earth days). MGS will now be deployed to study particularly interesting regions of Mars in more detail.
2001 February 27
The Witch Head Nebula
Credit & Copyright: Gary Stevens
Double, double toil and trouble; Fire burn, and cauldron bubble -- maybe Macbeth should have consulted the Witch Head Nebula. This suggestively shaped reflection nebula is associated with the bright star Rigel in the constellation Orion. More formally known as IC 2118, the Witch Head Nebula glows primarily by light reflected from Rigel, located just outside the top right corner of the above image. Fine dust in the nebula reflects the light. The blue color is caused not only by Rigel's blue color but because the dust grains reflect blue light more efficiently than red. The same physical process causes Earth's daytime sky to appear blue, although the scatterers in Earth's atmosphere are molecules of nitrogen and oxygen. The nebula lies about 1000 light-years away.
The Witch Head Nebula
Credit & Copyright: Gary Stevens
Double, double toil and trouble; Fire burn, and cauldron bubble -- maybe Macbeth should have consulted the Witch Head Nebula. This suggestively shaped reflection nebula is associated with the bright star Rigel in the constellation Orion. More formally known as IC 2118, the Witch Head Nebula glows primarily by light reflected from Rigel, located just outside the top right corner of the above image. Fine dust in the nebula reflects the light. The blue color is caused not only by Rigel's blue color but because the dust grains reflect blue light more efficiently than red. The same physical process causes Earth's daytime sky to appear blue, although the scatterers in Earth's atmosphere are molecules of nitrogen and oxygen. The nebula lies about 1000 light-years away.
2001 February 28
A Space Station Meets its Destiny
Credit: STS-98 Crew, NASA
The International Space Station (ISS) had a date with Destiny earlier this month. More specifically, the crew of the Space Shuttle Atlantis installed the science laboratory named Destiny on the ISS. Destiny, pictured here, will also serve as a control center for the Earth orbiting space station. To help install this module, space shuttle astronauts conducted the 100th space walk by an American, an event that occurred nearly 40 years after Ed White first ventured outside of his Gemini 4 spacecraft. The space shuttle's crew took the above picture after their spacecraft had undocked from the space station. Over two hundred kilometers below lies the Rio Negro region of Argentina.
A Space Station Meets its Destiny
Credit: STS-98 Crew, NASA
The International Space Station (ISS) had a date with Destiny earlier this month. More specifically, the crew of the Space Shuttle Atlantis installed the science laboratory named Destiny on the ISS. Destiny, pictured here, will also serve as a control center for the Earth orbiting space station. To help install this module, space shuttle astronauts conducted the 100th space walk by an American, an event that occurred nearly 40 years after Ed White first ventured outside of his Gemini 4 spacecraft. The space shuttle's crew took the above picture after their spacecraft had undocked from the space station. Over two hundred kilometers below lies the Rio Negro region of Argentina.
2001 March 1
Maximum Sun
Credit: SOHO - EIT Consortium, ESA, NASA
Astronomers recently witnessed an astounding, large scale solar event as the Sun's north and south magnetic poles changed places! But, this complete solar magnetic field flip was actually anticipated. It occurs every 11 years during the maximum of the solar activity cycle. Plagues of sun spots, flaring active regions, and huge prominences are also hard-to-miss signs that the solar maximum is here. On February 12, the sungazing SOHO spacecraft captured this dramatic image of a magnificent prominence above the Sun's limb. Seen at the lower right, streams of relatively cool dense plasma were lofted along looping magnetic field lines extending outward about 30 times the diameter of planet Earth. Far above the limb at the upper right, a disconnected ghostly arc surrounds a dark cavity with bright central emission. These features are telltale signs of a coronal mass ejection -- yet another violent expulsion of material from the active Sun. Enormous, intensely bright active regions also mottle the solar surface in this image, recorded in the light of energetic Helium atoms by SOHO's Extreme ultraviolet Imaging Telescope.
Maximum Sun
Credit: SOHO - EIT Consortium, ESA, NASA
Astronomers recently witnessed an astounding, large scale solar event as the Sun's north and south magnetic poles changed places! But, this complete solar magnetic field flip was actually anticipated. It occurs every 11 years during the maximum of the solar activity cycle. Plagues of sun spots, flaring active regions, and huge prominences are also hard-to-miss signs that the solar maximum is here. On February 12, the sungazing SOHO spacecraft captured this dramatic image of a magnificent prominence above the Sun's limb. Seen at the lower right, streams of relatively cool dense plasma were lofted along looping magnetic field lines extending outward about 30 times the diameter of planet Earth. Far above the limb at the upper right, a disconnected ghostly arc surrounds a dark cavity with bright central emission. These features are telltale signs of a coronal mass ejection -- yet another violent expulsion of material from the active Sun. Enormous, intensely bright active regions also mottle the solar surface in this image, recorded in the light of energetic Helium atoms by SOHO's Extreme ultraviolet Imaging Telescope.
2001 March 2
LkHa101: The Hole in the Doughnut
Credit: Peter Tuthill (Sydney University Physics Department) et al., W.M. Keck Observatory
You'd need a really big cup of coffee with this doughnut ... because the hole in the middle is about a billion kilometers across. Centered on the Sun, a circle that size would lie between the orbits of Mars and Jupiter. In fact, this doughnut is known to surround a massive newborn star cataloged as LkHa 101 which lies in the constellation Perseus. Imaged in infrared light, the tantalizing torus-shaped cloud of gas and dust is slightly tilted to our view. The cloud's material may well be the ingredients for the formation of a distant solar system. A bright source of ultraviolet light, the hot young star itself is much fainter in the infrared and so not visible in this picture. Still, the star's presence is indicated as its intense stellar wind and radiation has apparently carved out the doughnut's hole. This premier close-up of a stellar system in formation was accomplished by adapting a powerful observational technique called interferometry to planet Earth's largest single mirror telescope, the 10 meter Keck.
LkHa101: The Hole in the Doughnut
Credit: Peter Tuthill (Sydney University Physics Department) et al., W.M. Keck Observatory
You'd need a really big cup of coffee with this doughnut ... because the hole in the middle is about a billion kilometers across. Centered on the Sun, a circle that size would lie between the orbits of Mars and Jupiter. In fact, this doughnut is known to surround a massive newborn star cataloged as LkHa 101 which lies in the constellation Perseus. Imaged in infrared light, the tantalizing torus-shaped cloud of gas and dust is slightly tilted to our view. The cloud's material may well be the ingredients for the formation of a distant solar system. A bright source of ultraviolet light, the hot young star itself is much fainter in the infrared and so not visible in this picture. Still, the star's presence is indicated as its intense stellar wind and radiation has apparently carved out the doughnut's hole. This premier close-up of a stellar system in formation was accomplished by adapting a powerful observational technique called interferometry to planet Earth's largest single mirror telescope, the 10 meter Keck.
2001 March 3
Apollo 12 Visits Surveyor 3
Credit: Apollo 12 Crew, NASA
Apollo 12 was the second mission to land humans on the Moon. The landing site was picked to be near the location of Surveyor 3, a robot spacecraft that had landed on the Moon three years earlier. In the above photograph, taken by lunar module pilot Alan Bean, mission commander Pete Conrad retrieves parts from the Surveyor. The lunar module is visible in the distance. Apollo 12 brought back many photographs and moon rocks. Among the milestones achieved by Apollo 12 was the deployment of the Apollo Lunar Surface Experiments Package, which carried out many experiments including one that measured the solar wind.
Apollo 12 Visits Surveyor 3
Credit: Apollo 12 Crew, NASA
Apollo 12 was the second mission to land humans on the Moon. The landing site was picked to be near the location of Surveyor 3, a robot spacecraft that had landed on the Moon three years earlier. In the above photograph, taken by lunar module pilot Alan Bean, mission commander Pete Conrad retrieves parts from the Surveyor. The lunar module is visible in the distance. Apollo 12 brought back many photographs and moon rocks. Among the milestones achieved by Apollo 12 was the deployment of the Apollo Lunar Surface Experiments Package, which carried out many experiments including one that measured the solar wind.
2001 March 4
TT Cygni: Carbon Star
Credit: H. Olofsson (Stockholm Observatory) et al.
TT Cygni is a cool red giant star with a wind. This false-color picture of TT Cyg was made using a coordinated array of millimeter wavelength radio telescopes and shows radio emission from carbon monoxide (CO) molecules in the surrounding gas. The central emission is from material blown off the red giant over a few hundred years while the thin ring, with a radius of about 1/4 light-year, actually represents a shell of gas expanding outward for 6,000 years. Carbon stars like TT Cyg are so named for their apparent abundance of carbon containing molecules. The carbon is likely the dredged-up ashes of nuclear helium burning in the stellar interior. Carbon stars lose a significant fraction of their total mass in the form of a stellar wind which ultimately enriches the interstellar gas - the source of material for future generations of stars. TT Cyg is about 1,500 light-years away in the constellation Cygnus.
TT Cygni: Carbon Star
Credit: H. Olofsson (Stockholm Observatory) et al.
TT Cygni is a cool red giant star with a wind. This false-color picture of TT Cyg was made using a coordinated array of millimeter wavelength radio telescopes and shows radio emission from carbon monoxide (CO) molecules in the surrounding gas. The central emission is from material blown off the red giant over a few hundred years while the thin ring, with a radius of about 1/4 light-year, actually represents a shell of gas expanding outward for 6,000 years. Carbon stars like TT Cyg are so named for their apparent abundance of carbon containing molecules. The carbon is likely the dredged-up ashes of nuclear helium burning in the stellar interior. Carbon stars lose a significant fraction of their total mass in the form of a stellar wind which ultimately enriches the interstellar gas - the source of material for future generations of stars. TT Cyg is about 1,500 light-years away in the constellation Cygnus.
2001 March 5
Survivor: NEAR Shoemaker On Asteroid Eros
Credit: NEAR Project, NASA
Not part of a television game series, the NEAR Shoemaker spacecraft survived its unprecedented landing on an asteroid last month. As suggested in the illustration inset above, the car-sized probe likely rests gently on the tips of its solar panels having touched down under the influence of asteroid Eros' feeble gravity. Fortunately, the spacecraft's solar panels were bathed in sunlight and able to power NEAR's gamma-ray spectrometer. Perched on the asteroid, this instrument can determine the composition of Eros to a depth of about 10 centimeters with unanticipated accuracy by measuring the gamma-ray signatures of the atomic nuclei present. The data returned from the surface of Eros are plotted above and show clearly features corresponding to Iron, Oxygen, Silicon, and Potassium in the asteroid's regolith. Also briefly operating on Eros, NEAR's magnetometer has indicated that no surface magnetic field is discernible. Now turned off, NEAR Shoemaker could remain preserved in its present location, the vicinity of the huge, saddle-shaped feature dubbed Himeros, for billions of years. But, as the asteroid orbits, the spacecraft's solar panels will be repeatedly turned toward the Sun ... offering the possibility of reawakening this survivor.
Survivor: NEAR Shoemaker On Asteroid Eros
Credit: NEAR Project, NASA
Not part of a television game series, the NEAR Shoemaker spacecraft survived its unprecedented landing on an asteroid last month. As suggested in the illustration inset above, the car-sized probe likely rests gently on the tips of its solar panels having touched down under the influence of asteroid Eros' feeble gravity. Fortunately, the spacecraft's solar panels were bathed in sunlight and able to power NEAR's gamma-ray spectrometer. Perched on the asteroid, this instrument can determine the composition of Eros to a depth of about 10 centimeters with unanticipated accuracy by measuring the gamma-ray signatures of the atomic nuclei present. The data returned from the surface of Eros are plotted above and show clearly features corresponding to Iron, Oxygen, Silicon, and Potassium in the asteroid's regolith. Also briefly operating on Eros, NEAR's magnetometer has indicated that no surface magnetic field is discernible. Now turned off, NEAR Shoemaker could remain preserved in its present location, the vicinity of the huge, saddle-shaped feature dubbed Himeros, for billions of years. But, as the asteroid orbits, the spacecraft's solar panels will be repeatedly turned toward the Sun ... offering the possibility of reawakening this survivor.