Compared to the average motion, the Sun appears to move a little faster — 16,000 mph (25,200 km/h) — than the general rotation. It’s moving toward the galactic center at 22,000 mph (36,000 km/h) and slightly upward at 11,000 mph (18,000 km/h).
Binocular Universe web extra: 2009 celestial events to observe
With the New Year upon us, here are a few interesting events coming up between now and June that will be visible through our binoculars.
Observing Basics web extra: Glenn Chaple’s 2009 astronomy resolutions
1) Number one would be an ongoing thing — public outreach, in the form of my participation in public star parties. I already do this several times each year, but I would like to try to get involved in activities on April 2–5 (dates selected by the International Year of Astronomy [IYA] for 100 Hours of Astronomy) and the week of April 27–May 3 (the 2009 dates for Astronomy Week).
Fireball lights up the sky above western Canada
This video frame shows the November 21, 2008, fireball near its beginning. Richard Huziak and Gordon Sarty captured this image using the all-sky camera located on the roof of the physics building at the University of Saskatchewan.
Gordon Sarty
At about 5:30 P.M. local time November 20, hundreds of people across Alberta and Saskatchewan witnessed a brilliant fireball that lit up the darkening sky. Amateurs with digital devices as well as professionals using all-sky video cameras captured the spectacular sight. Such fireballs happen infrequently and only rarely over populated areas, making this a once- or twice-in-a-lifetime event for those under the incandescent debris.
Check out this CTV news story about the event, “Fire in the sky.”
The brief flashes of light typically seen during a meteor shower arise from pieces of interplanetary debris no bigger than a grain of sand. Bright meteors and fireballs — meteors that reach or exceed the approximate brightness of Venus — may be as big as a garden-variety pea. In contrast, the brilliant fireball over western Canada may have been a foot or two in diameter when it entered Earth’s atmosphere.
No one yet knows whether any pieces of this meteor survived the fiery passage through Earth’s protective blanket of air. Researchers suspect if any fragments reached the ground (where they officially would become meteorites), they likely would be found near the Alberta-Saskatchewan border. Once scientists examine the videos and determine the debris’ precise path, they can narrow the search zone to a reasonable size.
Richard Huziak and Gordon Sarty are two amateur astronomers that help maintain the all-sky meteor camera on the roof of the University of Saskatchewan physics building. See their video of the event below.
Bob Berman’s Strange Universe: Your planets in 2009
We’re attracted to the unusual. We never watch Congressional speeches, but we’d probably turn on C-SPAN if politicians dressed as hens. Same with the sky. We snap awake when the solar system cooks up a strange year. So happens, 2009 will deliver.
Phil Harrington’s Binocular Universe: Follow the Charioteer
The bright star Capella (Alpha [α] Aurigae) lights the top of our evening sky this month as it glides silently overhead. Shining at magnitude 0.08, Capella is the sixth-brightest star in the night sky. No wonder it draws so much attention all winter long.
Space and astronomy stories to watch for in 2009
Major astronomy and space events planned for 2009 include the first major test of the space shuttle replacement, a rendezvous of the Dawn spacecraft with Mars, and the launch of a roving laboratory to the Red Planet.
Stephen James O’Meara’s Secret Sky: A mirror image
This month, we’ll investigate some more of Herschel’s intriguing ring observations, as well as how the observer’s mind may have affected what he saw, or expected to see.
Chandrayaan-1 begins Moon observations
This image of the lunar polar region was taken by the TMC on November 15. Taken over the polar region of the Moon, the picture shows many large and small craters. To the lower left, is the brightly-lit rim of 73 mile-wide (117 kilometer) Moretus crater.
ISRO
November 24, 2008
The Indian Space Research Organisation’s lunar orbiter, Chandrayaan-1, released a probe that impacted close to the lunar south pole November 14. Following this, instruments on the orbiter are being turned on to get the science observations started.
The Indian Space Research Organisation’s lunar orbiter, Chandrayaan-1, released a probe that impacted close to the lunar south pole November 14. Following this, instruments on the orbiter are being turned on to get the science observations started.
Chandrayaan-1 dropped the Moon Impact Probe close to Shackleton crater near the south pole, where ice may exist in areas the Sun never illuminates. It carried three instruments: a video imaging system, a radar altimeter, and a mass spectrometer. The imaging system took pictures of the Moon as it approached the surface, the radar determined the altitude, and the mass spectrometer studied the thin lunar atmosphere.
After being released November 14, the probe took 25 minutes to reach the lunar surface. As it descended, the probe sent pictures to the orbiter that were later transmitted to Earth.
The Terrain Mapping Camera (TMC) and the Radiation Dose Monitor (RADOM) were functional by that time on the orbiter. After the probe’s impact, the remaining orbiter instruments began their commissioning activities.
During commissioning all standard operating modes of an instrument are exercised, and the data and housekeeping parameters are examined to verify that everything works properly.
The European near-infrared spectrometer SIR-2 was commissioned successfully November 19. The instrument was switched on and sent back housekeeping data indicating normal functionality. Science observations were started successfully November 20.
The Chandrayaan-1 X-ray Spectrometer (C1XS) was first activated November 23, and its commissioning is in progress.
The Sub-keV Atom Reflecting Analyzer (SARA) will be commissioned from December 7-10. The commissioning for this instrument will take longer than usual because the instrument operates at a high-voltage, which will be increased in steps.
A glimpse of the Milky Way
The Milky Way’s center dominates this view from the Spitzer Space Telescope. Two complementary Spitzer surveys reveal that the Milky Way produces stars at a faster pace than astronomers previously thought.
NASA/JPL-Caltech/University of Wisconsin
The Spitzer Space Telescope’s infrared eyes have delivered the best view of our galaxy’s inner regions that we likely will see for the foreseeable future. Because infrared light penetrates dust, the composite image shows the galactic plane out to 60,000 light-years from Earth — slightly more than double the distance to the Milky Way’s center.
To create the image, Spitzer scientists stitched together more than 800,000 snapshots. The image spans approximately 130° east to west (centered on the galaxy’s core) and up to 2° north and south of the plane. “This is the highest-resolution, largest, and most sensitive infrared picture ever taken of our Milky Way,” says Sean Carey of the Spitzer Science Center at the California Institute of Technology in Pasadena. “With this data, we can learn how massive stars form, map galactic spiral arms, and make a better estimate of our galaxy’s star-formation rate.”
The data came from two separate surveys: the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) and the Multiband Imaging Photometer for Spitzer Inner Galactic Plane Survey (MIPSGAL). In the final image, blue represents light of 3.6 micrometers, green shows light of 8 micrometers, and red reveals light of 24 micrometers. In comparison, visible light ranges from 0.4 to 0.7 micrometer.
The broad swaths of green reveal organic molecules known as polycyclic aromatic hydrocarbons. They encompass regions filled with developing stellar embryos. The curved ridges in the green clouds, dubbed bubbles, contain young stars. The stars themselves appear as yellow and red dots. And the reddish wisps filling most of the bubbles reveal particles of graphite dust. The blue specks sprinkled throughout the image are relatively old stars.
This image shows the Milky Way from approximately 65° galactic longitude (at left) to 39° longitude — Vulpecula to Aquila — and within 1° galactic latitude north and south of the galaxy’s plane. Click here to see a larger view.
All images by: NASA/JPL-Caltech/University of Wisconsin
This image shows the Milky Way from approximately 39° galactic longitude (at left) to 13° longitude — Aquila to northern Sagittarius — and within 1° galactic latitude north and south of the galaxy’s plane. The bright red-and-yellow complex at the top border and near the right edge is the Eagle Nebula (M16) in Serpens. Click here to see a larger view.
This image shows the Milky Way from approximately 13° galactic longitude (at left) to 347° longitude — from northern to southern Sagittarius and centered on galactic center — and within 2° galactic latitude north and south of the galaxy’s plane. Click here to see a larger view.
This image shows the Milky Way from approximately 347° galactic longitude (at left) to 321° longitude — southern Sagittarius to Circinus — and within 1° galactic latitude north and south of the galaxy’s plane. Click here to see a larger view.
This image shows the Milky Way from approximately 321° galactic longitude (at left) to 295° longitude — Circinus to western Centaurus — and within 1° galactic latitude north and south of the galaxy’s plane. Click here to see a larger view.
Mars Express maps aurorae on the Red Planet
An artist’s impression of how the ‘green’ aurorae may look to an observer orbiting on the night-side of Mars.
ESA/M. Holmström (IRF)
November 21, 2008
Scientists using the European Space Agency’s Mars Express have produced the first crude map of aurorae on Mars. These displays of ultraviolet light appear to be located close to the residual magnetic fields generated by Mars’ crustal rocks. They highlight a number of mysteries about the way Mars interacts with electrically charged particles originating from the Sun.
Scientists using the European Space Agency’s Mars Express have produced the first crude map of aurorae on Mars. These displays of ultraviolet light appear to be located close to the residual magnetic fields generated by Mars’ crustal rocks. They highlight a number of mysteries about the way Mars interacts with electrically charged particles originating from the Sun.
Mars Express’ Spectroscopy for Investigation of Characteristics of the Atmosphere of Mars (SPICAM) — the ultraviolet and infrared atmospheric spectrometer — discovered the planet’s aurorae in 2004.
Now Francois Leblanc, from the Service d’Aeronomie, France, and colleagues have announced the results of coordinated observation campaigns using SPICAM, the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS), and the Analyser of Space Plasmas and Energetic Atoms (ASPERA).
They observed nine new auroral emission events that allow them to make the first crude map of auroral activity on Mars. They see that the aurorae seem to be located near regions where the martian magnetic field is the strongest. MARSIS previously had observed higher-than-expected electrons in similar regions. This suggests that the magnetic fields help to create the aurorae.
On Earth, aurorae are more commonly known as the northern and southern lights. They are confined to the polar regions and shine brightly at visible as well as ultraviolet wavelengths. Similar aurorae exist on the giant planets of the solar system. They occur wherever a planet’s magnetic field channels electrically charged particles into the atmosphere.
In all of these planets, the magnetic fields are large-scale structures generated deep in the planet’s interior. Mars lacks such a large-scale internal mechanism. Instead, it just generates small pockets of magnetism where areas of rocks in the martian crust are magnetic. This results in many magnetic pole-type regions all over the planet.
Charged particles, likely electrons in this case, collide with molecules in the atmosphere and produce aurorae. The electrons almost certainly come from the Sun, which constantly blows out electrically charged particles into space. Known as the solar wind, this stream of particles provides the source of electrons to generate the aurorae, as the MARSIS and ASPERA results suggest.
But how the electrons are accelerated to sufficiently high energies to spark aurorae on Mars remains a mystery. “It may be that magnetic fields on Mars connect with the solar wind, providing a road for the electrons to travel along,” says Leblanc.
Any future astronauts expecting a spectacular light show, similar to aurorae on Earth, may be in for a disappointment. “We’re not sure whether the aurorae will be bright enough to be observed at visible wavelengths,” says Leblanc.
The molecules responsible for the visible light show on Earth — molecular and atomic oxygen and molecular nitrogen — are not abundant enough in the martian atmosphere. SPICAM is designed to work at ultraviolet wavelengths and cannot see whether visible light is being emitted as well.
Nevertheless, there is plenty of work for the scientists to do.
“There’s now a large domain of physics that we have to explore in order to understand the aurorae on Mars. Thanks to Mars Express we have a lot of very good measurements to work with,” said Leblanc.
NASA spacecraft detects buried glaciers on Mars
Artist concept of glacier on Mars.
NASA/JPL
November 21, 2008
NASA’s Mars Reconnaissance Orbiter has revealed vast martian glaciers of water ice under protective blankets of rocky debris at much lower latitudes than any ice previously identified on the Red Planet.
NASA’s Mars Reconnaissance Orbiter has revealed vast martian glaciers of water ice under protective blankets of rocky debris at much lower latitudes than any ice previously identified on the Red Planet.
Scientists analyzed data from the spacecraft’s ground-penetrating radar and discovered that buried glaciers extend for dozens of miles from the edges of mountains or cliffs. The group reported the results in the November 21 issue of the journal Science. A layer of rocky debris blanketing the ice may have preserved the underground glaciers as remnants from an ice sheet that covered middle latitudes during a past ice age. This discovery is similar to massive ice glaciers that have been detected under rocky coverings in Antarctica.
“Altogether, these glaciers almost certainly represent the largest reservoir of water ice on Mars that is not in the polar caps,” said John W. Holt of the University of Texas at Austin, who is lead author of the report. “Just one of the features we examined is three times larger than the city of Los Angeles and up to half a mile thick. And there are many more. In addition to their scientific value, they could be a source of water to support future exploration of Mars.”
Scientists have been puzzled by what are known as aprons — gently sloping areas containing rocky deposits at the bases of taller geographical features — since NASA’s Viking orbiters first observed them on the martian surface in the 1970s. One theory suggests the aprons are flows of rocky debris lubricated by a small amount ice. Now, the shallow radar instrument on the Mars Reconnaissance Orbiter has provided scientists an answer to this martian puzzle.
“These results are the smoking gun pointing to the presence of large amounts of water ice at these latitudes,” said Ali Safaeinili, a shallow radar instruments team member with NASA’s Jet Propulsion Laboratory in Pasadena, California.
The spacecraft received radar echoes that indicate radio waves pass through the aprons and reflect off a deeper surface below without significant loss in strength. That is expected if the apron areas are composed of thick ice under a relatively thin covering. The radar does not detect reflections from the interior of these deposits as would occur if they contained significant rock debris. The apparent velocity of radio waves passing through the apron is consistent with a composition of water ice.
Scientists developed the orbiter’s shallow radar instrument to examine these mid-latitude geographical features and layered deposits at the martian poles. The Italian Space Agency provided the device.
“We developed the instrument so it could operate on this kind of terrain,” said Roberto Seu, leader of the instrument science team at the University of Rome La Sapienza in Italy. “It is now a priority to observe other examples of these aprons to determine whether they are also ice.”
Holt and 11 co-authors report the buried glaciers lie in the Hellas Basin region of Mars’ southern hemisphere. The radar also has detected similar-appearing aprons extending from cliffs in the northern hemisphere.
“There’s an even larger volume of water ice in the northern deposits,” said JPL geologist Jeffrey J. Plaut, who will publish results about these deposits in the American Geophysical Union’s Geophysical Research Letters. “The fact these features are in the same latitude bands, about 35 to 60 degrees in both hemispheres, points to a climate-driven mechanism for explaining how they got there.”
The rocky debris blanket topping the glaciers apparently has protected the ice from vaporizing, which would happen if it were exposed to the atmosphere at these latitudes.
“A key question is, how did the ice get there in the first place?” said James W. Head of Brown University in Providence, Rhode Island. “The tilt of Mars’ spin axis sometimes gets much greater than it is now. Climate modeling tells us ice sheets could cover mid-latitude regions of Mars during those high-tilt periods. The buried glaciers make sense as preserved fragments from an ice age millions of years ago. On Earth, such buried glacial ice in Antarctica preserves the record of traces of ancient organisms and past climate history.”