Updated 09-Nov-10 18:43
|Interesting Organizations||WEB Sites|
|Space Weather Bureau, Science NASA||http://www.spaceweather.com/|
|Max-Planck-Institute, Plasmaphysics, Heidelberg||http://www.mpi-hd.mpg.de|
|Max-Planck-Institute, Planetology, Heidelberg||http://galileo.mpi-hd.mpg.de|
|Astronomical Observatory, Heidelberg||http://www.lsw.uni-heidelberg.de|
|Kepler's Museum, Weil der Stadt||http://www.sjsu.edu/depts/Museum/kep.html|
|Astronomy Magazine, Kalmbach||http://www.astronomy.com/|
|Interesting Books:||WEB Sites:|
A Guide to the Stars, Constellations, and the Planets;
Caxton Editions, London 2000;
450 illustrations (incl. 370 in color); 232 pages;
obtainable from Heffers, Cambridge, England, at £7.99
Sterling Publishing Company, New York, N.Y., paper, 224 pages, 2000; $14.95;
obtainable from Heffers, Cambridge, England, at £11.99 (about 50 DM, German currency)
Atlas of the Moon;
Aventinum, Praha, Czech Republic, 1992;
out of print (ask Heffers for secondhand copies)
|Oldrich HLAD, Frantisek HOVORKA,
Petr SOJKA & Jitka WEISELOVA:
Sky Map 2000.0 (a Wall Map);
Publishing House ZES Brno & Astronomical
Observatory and Planetarium, Prague, Czech
Republic, 1st edition 1998;
The Moon (a Wall Map);
Publishing House ZES Brno & Astronomical
Observatory and Planetarium, Prague, Czech
Republic, 1st edition 1999, 30 years after
Apollo 11; ISBN 80-86017-21-4
|Oldrich HLAD, Frantisek HOVORKA,
Petr SOJKA & Jitka WEISELOVA: ATLAS COELI NOVUS 2000.0;
Sky Atlas on 40 large 2-sided sheets (24.6" by 17.7" = 62.5cm by 45cm), & Catalogue of 85,000 objects on CD;
ETC Publishing Prague & Astronomical
Observatory and Planetarium, Prague, Czech
Republic, 1st edition 1998;
ISBN 80-86006-51-4 (ETC Publishing),
ISBN 80-86017-09-5 (OaP Praha).
|Patrick MOORE: 2009
Yearbook of Astronomy;
MacMillan Publishers 2008, 366 pages; paper ISBN 978-0-230-71441-0;
|Date||Event in January 09 see Astronomy Magazine, December 2008, Astronomy Guide 2009, page III; http://www.astronomy.com/asy/default.aspx?c=a&id=7674|
|2:||The Moon passes 5° north of Uranus|
|3:||Quadrantid meteor shower peaks|
|4:||Mercury is at greatest eastern elongation (19°)|
|14:||Venus is at greatest eastern elongation (47°)|
|15:||The Moon passes 6° south of Saturn|
|18:||Asteroid Juno is in conjunction with the Sun|
|20:||Mercury is in inferior conjunction|
|21:||Antares is 0.02" south of the Moon (occultation)|
|23:||Venus passes 1.4° north of Uranus|
|24:||Jupiter is in cojunction with the Sun|
|26:||Annular solar eclipse|
|27:||The Moon passes 1.8° north of Neptune|
|29:||The Moon passes 5° north of Uranus|
|30:||The Moon passes 3° north of Venus|
|?, ? APR||Class: Heidelberg-PATTON, evening observations, 21 - 22:30h|
|Object||Description, Position etc.|
|Arcturus||α of Bootes,
red giant with strong IR radiation, the brightest star of the northern
hemisphere, apparent magnitude -0.04; we have seen
this orange star (originally thought it was Mars)
close to western horizon. Very close: 36.7 light
years (=11.3 parsec), It is now almost at its closest point to the Sun, and
is moving rapidly (122 km/s) relative to the solar system.
Its mass is 1-1.5 solar masses, its diameter 15.9x
bigger than Sun - the orbit of Mars fits into it and leaves 15% (see
the view below). It is 110 times (with
IR 180 times) more luminous than the Sun,
but cooler (4,300 K). Apparently older than the Sun ->
4.6 × 109
http://en.wikipedia.org/wiki/Arcturus Location among red giants within the H-R-Diagram, Textbook Fig. 8-7, page 152, Fig. 10-3, p. 199.
|Vega||α of Lyra, we have seen it above our heads. TB p. 14, 18, 20, 110, 153|
|Deneb||α of Cygnus, the Swan (cross-shaped constellation westwards from Cassiopeia);|
|Jupiter||Very low in the southern sky, currently within the constellation Scorpius|
|Ursa Major||Big Bear = Big Dipper|
|Cassiopeia||Circum-polar Constellation - the famous "W", pointing to the Polaris;|
|Milky Way||Milky Way galaxy, TB p. 250|
|Andromeda||Circum-polar Constellation southwards from Cassiopeia; contains Andromeda Galaxy (M 31), TB p. 250 - right down from Cassiopeia,|
|When to view the planets in January 09:|
|Mercury (southwest)||Saturn (east)||Saturn (southwest)|
CONJUNCTION: When the sun goes down on Sunday, April 26th, step outside and
look west. An exquisitely-slender crescent Moon is lining up with
Mercury and the Pleiades star cluster for a
three-way conjunction in the sunset sky. Click here for the full story and a sky
UNEXPECTED SOLAR ACTIVITY: The Sun produced an unexpected burst of activity on April 23rd when an enormous prominence rose over the northeastern limb and erupted. A coronal mass ejection (CME) billowed away from the blast site, but the billion-ton cloud is not heading toward Earth. Visit http://spaceweather.com for movies of the event.
Green comet approaches Earth
Richard Talcott, senior Editor of Astronomy:
Spot and follow the years's brightest comet with Astronomy.com
In 1996, a 7-year-old boy in China bent over the eyepiece of a small telescope and saw something that would change his life — a comet of flamboyant beauty, bright and puffy with an active tail. At first he thought he himself had discovered it, but no, he learned, two men named "Hale" and "Bopp" had beat him to it. Mastering his disappointment, young Quanzhi Ye resolved to find his own comet one day.
And one day, he did.
Fast forward to a summer afternoon in July 2007. Ye, now 19 years old and a student of meteorology at China's Sun Yat-sen University, bent over his desk to stare at a black-and-white star field. The photo was taken nights before by Taiwanese astronomer Chi Sheng Lin on "sky patrol" at the Lulin Observatory. Ye's finger moved from point to point — and stopped. One of the stars was not a star, it was a comet, and this time Ye saw it first.
Comet Lulin, named after the observatory in Taiwan where the discovery-photo was taken, is now approaching Earth. "It is a green beauty that could become visible to the naked eye any day now," said Ye.
The comet makes its closest approach to Earth (0.41 AU) February 24, 2009. Current estimates peg the maximum brightness at 4th or 5th magnitude, which means dark country skies would be required to see it. No one can say for sure, however, because this appears to be Lulin's first visit to the inner solar system and its first exposure to intense sunlight. Surprises are possible.
color comes from the gases that make up its Jupiter-sized atmosphere. Jets
spewing from the comet's nucleus contain cyanogen (CN — a poisonous gas found in
many comets) and di-atomic carbon (C2). Both substances glow green
when illuminated by sunlight in the near-vacuum of space.
In 1910, many people panicked when astronomers revealed Earth would pass through the cyanogen-rich tail of Comet Halley. False alarm. The wispy tail of the comet couldn't penetrate Earth's dense atmosphere; even if it had penetrated, there wasn't enough cyanogen to cause real trouble. Comet Lulin will cause even less trouble than Halley did. At closest approach in late February, Lulin will stop 61 million kilometers short of Earth, utterly harmless.
To see Comet Lulin with your eyes, set your alarm for 3 a.m. The comet rises a few hours before the Sun and may be found about one-third of the way up the southern sky before dawn. Here are some dates when it is especially easy to find:
February 16th: Comet Lulin passes Spica in the constellation Virgo. Spica is a star of first magnitude and a guidepost even city astronomers cannot miss. A finder scope pointed at Spica will capture Comet Lulin in the field of view, centering the optics within a nudge of both objects.
February 24th: Closest approach! On this special morning, Lulin will lay just a few degrees from Saturn in the constellation Leo. Saturn is obvious to the unaided eye, and Lulin could be as well. If this doesn't draw you out of bed, nothing will.
Ye notes that Comet Lulin is remarkable not only for its rare beauty, but also for its rare manner of discovery. "This is a 'comet of collaboration' between Taiwanese and Chinese astronomers," he said. "The discovery could not have been made without a contribution from both sides of the Strait that separates our countries. Chi Sheng Lin and other members of the Lulin Observatory staff enabled me to get the images I wanted, while I analyzed the data and found the comet."
Click on Astronomy's StarDomePlus .
|How low can the Moon go? From: Astronomy Magazine|
If you've been watching the Moon after sunset in the 3rd September week, you may have noticed it lies lower in the sky than usual (at least if you live at mid-northern latitudes). It's not your imagination — the Moon is figuratively scraping the treetops this week. Although this is no great mystery, it never hurts to remind yourself about the Moon's monthly and yearly cycles.
The Moon's maximum altitude from any given location depends on its declination — how far north or south of the celestial equator it lies. And because the Moon orbits Earth in nearly the same plane as Earth orbits the Sun, our satellite's declination hinges mainly on its phase and the time of year.
This shows up most noticeably at Full Moon. In December, for example, when the Sun lies near the winter solstice, the Full Moon lies near the summer solstice. So, just like the Sun in June, December's Full Moon passes closer to the zenith than any other Full Moon. The reverse also holds true: June's Full Moon lies near the winter solstice, so it takes a low arc across the sky.
The same thing holds true at other lunar phases. In the 3rd September week, we experienced a First Quarter Moon. By definition, that means the Moon has moved one-quarter of the way around its orbit relative to the Sun. And because the Sun reaches the autumnal equinox on September 21, the First Quarter Moon lies near the winter solstice. The result: a low Moon after sunset. The effect is more pronounced this year because the Moon currently lies 5° south of the ecliptic (see Fig. 3-12, page 38 of our Textbook), about as far south as it gets.
How much difference does this make? This week's First Quarter Moon appeared barely 20° above the horizon at sunset for an observer at 40° north latitude. Last March, the First Quarter Moon appeared nearly 80° above the horizon — just over 10° from the zenith.
posted by Rich Talcott
Question by Jiri Brezina: And how high was the
First Quarter Moon for an observer at our, 50° north latitude? Higher or
Answer: 10° lower = 70° above the horizon.
JWST, the James
Webb Space Telescope, will be a large infrared telescope with a 6.5-meter
primary mirror. Launch is planned for 2013. JWST will reside in an orbit about
at L2 (Lagrangian point
2), 1.5 million km from the Earth. Its 6.5 meter-diameter mirror consists of
18 hexagonal segments, each 1.3 meters in diameter, approximately 20 kg.
These extremely lightweight mirrors are made of beryllium, the lightest hard metal we know.
A picture is worth a 1000 words. In the magnetic map of the Sun, below, N is white and S is black. The backward sunspot is circled:
Above: A SOHO magnetogram of the Sun. July 31, 2006.
This tiny spot of backwardness matters because of what it might foretell: A really big solar cycle.
Solar activity rises and falls in 11-year cycles, swinging back and forth between times of quiet and storminess. Right now the sun is quiet. "We're near the end of Solar Cycle 23, which peaked way back in 2001," explains Hathaway. The next cycle, Solar Cycle 24, should begin "any time now," returning the Sun to a stormy state.
Satellite operators and NASA mission planners are bracing for this next solar cycle because it is expected to be exceptionally stormy, perhaps the stormiest in decades. Sunspots and solar flares will return in abundance, producing bright auroras on Earth and dangerous proton storms in space: full story.
But when will Solar Cycle 24 begin?
"Maybe it already did - on July 31st," says Hathaway. The first spot of a new solar cycle is always backwards. Solar physicists have long known that sunspot magnetic fields reverse polarity from cycle to cycle. N-S becomes S-N and vice versa. "The backward sunspot may be the first sunspot of Cycle 24."
It sounds exciting, but Hathaway is cautious on several fronts:
First, the sunspot lasted only three hours. Typically, sunspots last days, weeks or even months. Three hours is fleeting in the extreme. "It came and went so fast, it was not given an official sunspot number," says Hathaway. The astronomers who number sunspots didn't think it worthy!
The SkyScout is a revolutionary handheld device that uses advanced GPS technology with point and click convenience to identify thousands of stars, planets, constellations and more.
Simply point the SkyScout at any star in the sky and click the "target" button.
The SkyScout will tell you what object you are looking at.
To locate a star or planet, select the object's name from the menu and follow the directional arrows through the viewfinder.
SkyScout tells you when you are on target. It's that easy!
Once you have targeted an object the real fun begins.
The SkyScout includes entertaining and educational audio and text information, including facts, trivia, history and mythology about Celestron's most popular celestial objects.
A fun learning tool for all ages, the SkyScout personal planetarium puts the knowledge of an expert astronomer in the palm of your hand.
I purchased this unusual gadget in July 2006 and received it by the end of December 2006 (so long was the waiting time). My experience: it is fantastic, OK, but: the pointing is not that easy as advertized, one must be at least 30 meters distant from a large metallic object (car etc.) in order to avoid magnetic interference and batteries last a few hours of operation only. I decided to purchase a similar instrument from Meade, mySKY Plus, currently at $149 (Celestron's SkyScout is now at $199), whose batteries should last longer and pointing should be easier, so I'll test it.
Wednesday (25-JAN-06) announced the discovery of what is possibly the smallest
planet known outside our solar system orbiting a normal star, an exoplanet. Its
orbit is farther from its host star than Earth is from the Sun. Most known
extrasolar planets reside inside the equivalent of Mercury’s orbit. The planet
is estimated to be about 5.5 times as massive as Earth and thought to be rocky.
It orbits a red dwarf star, about 28,000 light-years away from us. Red dwarfs
are about one-fifth as massive as the Sun and up to 50 times fainter. But they
are among the
most common stars in the universe. So the finding suggests rocky
worlds may be common. "The team has discovered the most Earthlike planet yet,”
said Michael Turner, assistant director for the mathematical and physical
sciences directorate at the National Science Foundation, which supported the
work. The discovery is detailed in Thursday's issue of the journal
More to come
Prior to this discovery, the smallest extrasolar planet found around a normal star was about 7.5 Earth masses. Earth-sized planets have been detected, but only around dying neutron stars. The newfound planet, named OGLE-2005-BLG-390Lb, is probably too cold to support life as we know it, astronomers said. With a surface temperature of 364 degrees below zero Fahrenheit (-220 degrees Celsius), it is nearly as frigid as Pluto.
was discovered using a technique called “gravitational
microlensing,” whereby light from a distant star is bent and magnified by
the gravitational field of a foreground star. The presence of a planet around
the foreground star causes light from the distant star to become momentarily
Since star alignments are unique events, a microlensing experiment can never be repeated. Todd Henry, an astronomer at Georgia State University who was not involved in the study, said the discovery was an “intriguing result from this particular technique, but unfortunately you can’t follow it up.” Many astronomers view the lack of repeatability as an acceptable trade-off, however, because thousands of star systems can be screened in a relatively short period of time compared with other techniques. “You can’t learn a whole lot about the details of individual systems … but it’s a wonderful alternative for learning about what the mass distribution of extrasolar planets might be and the frequency at which they occur,” said David Latham, an astronomer at the Harvard-Smithsonian Center for Astrophysics who was not part of the study.
In a telephone interview, Jean-Phillipe Beaulieu, a co-author in the study, said that while the observations can never be repeated, the discovery was simultaneously verified by different telescopes around the world. The microlensing event was detected July 11 by telescopes in the OGLE (Optical Gravitational Lensing Experiment) project. Planet-hunters are very protective of their data, and cooperation between different teams is rare. But astronomers around the globe were alerted so that the event could be detected by multiple telescopes. “The only way to realize the full scientific benefit of our observations is to share the data with our competition,” said Paczynski, an OGLE co-founder. Overall, the study involved 73 researchers from 32 institutions worldwide. “The fact that they’ve got a whole bunch of folks using multiple telescopes all observing the same event and calibrating themselves self-consistently makes the data look very sound,” Boss said. “I think it’s a pretty solid detection.”
Astronomers hailed the discovery as the first of a new class of small, rocky worlds located at far-out distances from their stars. The planet and star are separated by about 2.5 astronomical units. One AU is equal to the distance between the Earth and the Sun. Until now, no small planet had been found farther than 0.15 AU from its parent star.
The finding means planet hunters are one step closer to detecting their holy grail: a habitable Earthlike planet that can sustain liquid water and support life. "We may predict with reasonable probability that microlensing will discover planets with masses like that of Earth at a similar distance from their stars and with comparable surface temperature," said study co-author Bohdan Paczynski from Princeton University.
ASTR-100 texbook pages: 359 - 361. Also, read http://www.msnbc.msn.com/id/11013519/ http://www.newscientistspace.com/article/dn7517
AMAZING CASSINI PICTURES OF SPONGY MOON HYPERION! These stunning images of Saturn's moon Hyperion taken by the Cassini spacecraft 26-SEP-05, show a surface dotted with craters and modified by some process, not yet understood, to create a strange, "spongy" appearance, unlike the surface of any other moon in our Solar System. http://spaceflightnow.com/cassini/051002hyperion.html
MOON DISCOVERED ORBITING SOLAR SYSTEM'S 10TH PLANET
The newly discovered 10th planet, 2003 UB313, with a catchy code name Xena (after the TV warrior princess), is the Solar System's farthest detected planet: 97 AU. Now, the team of Michael E. Brown (California Institute of Technology), the discoverer of Xena, have discovered it has a moon, nicknamed "Gabrielle" - after the fictional Xena's sidekick. Xena is thought to be about 2700 km in diameter (Pluto is 2274 km), and may be around 250 km accross. http://spaceflightnow.com/news/n0510/02xenamoon/ http://www.space.com/scienceastronomy/050729_new_planet.html
Timothy J. Stubbs, Richard R. Vondrak, and William M. Farrell of the Laboratory for Extraterrestrial Physics at NASA's Goddard Space Flight Center recently proposed a dynamic fountain model for lunar dust:
"The Moon seems to have a tenuous atmosphere of moving dust particles," Stubbs explains. "We use the word 'fountain' to evoke the idea of a drinking fountain: the arc of water coming out of the spout looks static, but we know the water molecules are in motion." In the same way, individual bits of moondust are constantly leaping up from and falling back to the Moon's surface, giving rise to a "dust atmosphere" that looks static but is composed of dust particles in constant motion."
The ESA's (European Space Agency) probe
Huygens landed on the Saturn's biggest moon Titan on 14-JAN-05. This moon is
unique by its atmosphere: it is at least 40% thicker (higher pressure) than that
of the Earth. But Earth is a planet, 2.5x greater than Titan. Titan is the
2nd biggest satellite of the Solar System (after Ganymede, the satellite of
Jupiter). Sunday, the first pictures of the fascinating surface have been
You may also listen the sound from there:
ESA just created this unique MacroMedia
around Saturn. You may change the view from Top to Side and back without
interrupting the motion. High speed PCs (3 GHz is fine) present a smooth motion
even with the highest quality view. Slower PCs may improve the motion by using
medium or low quality (right click on the animation, choose one of the 3 quality
IAPETUS, a smaller but mysterious Moon of Saturn: close views by Cassini spacecraft
In the Greek mythology, Iapetus was the son of Uranus and Gaia. Iapetus' wife was Clymene, with whom he had four children - Atlas, Menoetius, Prometheus and Epimetheus. He is occasionally called the husband of Asia or Asopis.
Iapetus, discovered and named 1671 by Giovanni Domenico Cassini, is a very mysterious - two-faced - moon of Saturn. The ESA's spacecraft Cassini - Huygens, took fascinating views of this moon after the spacecraft's closest approach to the icy moon during a close flyby on New Year's Eve 2004.
Cassini observed also a giant landslide on Iapetus:
See: Astronomy (published by Kalmbach , Waukesha, WI 53197-9950) 26/1998, 11/November: "Blindsiding Earth", p. 32, 34; http://www.astronomy.com
University of Hawaii planetary astronomers have discovered what appears to be the first of a new class of threatening asteroid whose members orbit the Sun inside Earth's orbit. They pose a large threat to Earth because they are hard to find - they can always be seen near the horizon, just before sunrise or just after sunset. The new asteroid 1998 DK36 seems to be about 40 meters (130 feet) across, slightly smaller than the asteroid that flattened 700 square miles of Siberian forest in 1908. This one never comes closer than 750,000 miles from Earth's orbit. Those asteroids whose orbits intersect Earth's orbit could sneak up and blindside Earth from the daytime hemisphere without us ever knowing there were approaching.
In July, astronomers found three more "potentially hazardous asteroids" in more typical orbit, raising the total to 128. NASA recently established a program office at Jet Propulsion Laboratory to locate within the next decade 90% of the estimated 2,000 asteroids that could cause global disaster.
The Minor Planet Center (MPC) operates at the Smithsonian Astrophysical Observatory, under the auspices of Commission 20
of the International Astronomical Union (IAU) and is a nonprofit organization, with principal funding coming from subscriptions to
the various services offered by the Center. The MPC is responsible for the efficient collection,
(computation), checking and dissemination of astrometric observations and orbits for minor planets and comets, via the Minor Planet Circulars (issued
monthly) and the Minor Planet Electronic Circulars (issued as necessary).
See: Astronomy (Kalmbach Pub., Waukesha, WI 53197-9950)
26/1998, 11/November: "SOHO Phones Home", p. 36;
Astronomy 26/1998, 2/February: "Sun Shines on SOHO and Spartan", p. 32;
The Solar and Heliospheric Observatory (SOHO) answered radio signals send by a Deep Space Network antenna in Australia. Ground controls lost contact with the $1 billion spacecraft on 24 June (see Astronomy 10/October 98, AstroNews).
In mid-October 1998, two of SOHO's 12 scientific instruments, the Michelson Doppler Imager (MDI) and Extreme-ultraviolet Imaging Telescope (EIT), took the spacecraft's first pictures. As of November 5, 1998, all 12 instruments had been switched on and recommissioned. Except for a slight degradation, all were functioning as they were before the loss of contact. Scientists were astounded by the lack of damage. While out of commission, SOHO's onboard instruments experienced extreme temperatures: from 100°C (210°F) to -100°C (-150°F), even the fuel tanks froze.
About Milky Way Galaxy and classification of galaxies, see
ASTR-100 textbook: Michael A. Seeds, Horizons, Exploring the Universe,
Thomson Brooks/Cole, edition 9, 2006, p. 252 - 301, especially p. 284 - 285;
about Edwin Hubble see Astronomy, 27/1999, 2/February, Mastering the Universe by Gale Christianson, p. 60 - 65.
Our Milky Way Galaxy is a star system roughly 75,000 light years in diameter, containing about 200 billion stars. Edwin Hubble classified the galaxies according to their shapes and summarized the classification in a diagram known today as the tuning fork diagram including the following galaxy types: elliptical (E), spiral (S), barred spiral (SB) and irregular (Irr). Our Milky Way Galaxy has been always thought to be the simple spiral.
New studies prove it has a large bar running right through its center.
See: Science (AAAS, Washington D.C.), vol. 282, Nr. 5390/30
Oct. 98, p. 839
While the last planet of our solar system has been Pluto (the outermost & smallest planet, or a Kuipers Belt body?), discovered by Clyde Tombaugh 1930, since 1995, more than 12 extrasolar planets have been confirmed by now. The above site quotes links to the Web sites of all planetary search programs, as well as a bibliography of more than 750 papers related to distant worlds. Visitors can download tutorials on how astronomers pursue their quarry and the physical properties that may make other planets habitable. The goal is to "create a cooperative spirit among researchers in this field, says astronomer Jean Schneider, the site's coordinator. Steven Vogt of the University of California, Santa Cruz, cautions that some of the site's advertised "planets" aren't peer reviewed, and a few have vanished under scientific scrutiny.
From: Astronomy 27/1999, 3/March: "King of the Mountain" by Govert Schilling.
Europe (ESO) is building a huge telescope in the Chilean Andes that's destined to be the finest in the world.
See also: "Sky
Show" by Martin Ratcliffe and Alister Ling,
Astronomy 27/1999, 2/February, p. 68 - 77
Pluto recently left its 20-year period of being closer to the Sun than Neptune: 21 January '79 through 14 March '99. On 14 March '99, Pluto was at the same distance from the Sun (4,5 billion kilometer) as Neptune. In 1989 it reached perihelion and was only 29.64 AU from the Sun; it ventures as far as 49.24 AU from the Sun at aphelion in the year 2112. Plutos orbit (its period = 247.7 years) is less circular and more inclined to ecliptic than that of any planet in our solar system. At perihelion (when closest to the Sun), Pluto gets thin atmosphere of nitrogen, carbon monoxide & methane. As Pluto moves farther from the Sun, its atmosphere freezes, its surface gets white due to snow of methane. The closer to the Sun, photochemic reactions caused by Sun's ultraviolet radiation, over the years, turned it dark. Thus Pluto grows intrinsically (and even apparently) brighter as it moves away from the Sun. Pluto spins slowly on its more than "horizontally" tilted (118°) axis: Plutos day is 6 days, 9 hours, and 18 minutes. It has one satellite, Charon, whose orbit (similarly as Pluto's equator) is perpendicular to the Pluto's orbit, with the same orbital period as the Plutos day; therefore, for an observer on the Plutos surface, Charon remains locked in the same position above the horizon (similar to the geo-stationary position of TV-satellites on the Earth). From Pluto, Charon looks sixty times larger than Earths Moon. Twice during each revolution of Pluto around the Sun, Charons orbital plane is edge-on to Earth; it is during these times that we see Pluto and Charon eclipsing each other. Its recent eclipse cycle of 6 years, 1985-91, enabled to improve data on size & density of the both bodies and unique observations of Plutos temporary atmosphere.
Pluto & Charon match the properties of the Kuiper Belt Objects:
Relatively to Pluto, Charon (about the half
Plutos size) is the largest satellites of the Solar system; thus, Pluto & Charon
are almost a double (binary) planet, the common center of revolution is between
both the bodies. Pluto is the only planet, which has been not yet visited by any
spacecraft. Two special probes Pluto Express should be launched by NASA in 2001,
to reach Pluto at about 15,000 km distance in 2013, at an interval of about 6 months.
http://www.jpl.nasa.gov/pluto/ ; http://www.lpl.arizona.edu/pluto/ ;
Other data on Pluto:
Astronomy: Jul 86, 7-22; Jan 94, 40-47;
Alan STERN & Jacqueline MITTON, Pluto and Charon; Ice worlds on the ragged edge of the Solar System;
J. Wiley & Sons, N.Y., 1998; 223 pages; ISBN 0-471-15297-8;
© Graphic by T-Online: http://www.t-online.de/bildung/index/wisbix34.htm
f_trips.htm#Total Solar Eclipse, August 11
Recently a series of gamma bursts coming to us from great distances (edge of the Universe) are explained as gamma flashes from dying stars, supernovas.
consisting of Coronal Mass Ejections (CMEs), auroras, geomagnetic storms, etc. - see http://www.spacescience.com/ etc..
One of the best images of the Jupiter moon Io made recently by Galileo:
AEROGEL - the lightest solid
In the lower photograph, a flame can 'levitate' the aerogel plate carying a few crayons.
From: Space Weather News for May 10, 2002
(copy of the original text)
A PLANETARY REMINDER: As the sky fades to black on Friday evening, May
10th, Venus and Mars will pop out of the twilight a mere one-third of a degree apart. (The tip of your pinky held at arms length is about twice that wide.) It's a rare opportunity to peer through a telescope and see two planets at once -- or simply enjoy them with your unaided eye. Look toward the west after sunset to find the pair. Visit SpaceWeather.com for more information and recent images of the ongoing planet show.