CLOSE ENCOUNTER WITH JUPITER

 

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CLOSE ENCOUNTER WITH JUPITER: Tonight, Earth and Jupiter converge for their closest encounter until 2022. The giant planet will soar overhead at midnight, outshining everything except the Moon itself. At this time, even a small telescope pointed at Jupiter will reveal the planet's moons, cloud belts and swirling storms. Take a look!
If Jupiter is up at midnight, it must be opposite the sun: diagram. Indeed, astronomers call this "Jupiter's night of opposition." The effect of opposition may be seen in the shadow of Jupiter's moon Io, shown here in a photo taken last night by Anthony Wesley of Australia:

"Io was almost on top of its own shadow," points out Wesley. "This is due to the near-perfect alignment of Jupiter, Earth and the sun."

In a coincidence of interplanetary proportions, Uranus is also at opposition tonight. This rare double opposition of two giant planets is a once-in-a-lifetime event. Unlike Jupiter, Uranus is barely visible to the naked eye, a result of its smaller size and greater distance. It looks great, however, through a small telescope. Just point your optics at Jupiter and you will find emerald Uranus about 1^o away.

more images: from Alan Friedman at the Mt. Wilson Observatory in California; from Pete Lawrence of Selsey, West Sussex, UK; from Efrain Morales Rivera of Aguadilla, Puerto Rico; from Sadegh Ghomizadeh of Iran Tehran; from Jerôme Grenier of Paris, France; from Frank Olsen of Tromvik, Norway; from Jimmy Eubanks of Boiling Springs, SC; from Mark Humpage of Lutterworth, UK; from P. Nikolakakos of Sparta, Greece;
SPACE STATION RADAR ECHO: The US Air Force Space Surveillance Radar is scanning the skies above the USA for Earth-orbiting objects. Yesterday, Sept. 19th at 16:09 UT, the International Space Station flew through the radar's primary beam, producing a strong echo. Click on the dynamic spectrum to listen: BUSCARLO EN LA DIRECCION

"SpaceWeather.com"

The sound you just heard came from the loudspeaker of a receiver in Roswell, New Mexico, operated by radio engineer Stan Nelson. "The ISS was passing over Lubbock, Texas--midway between me and the Air Force radar," he says. "It was the perfect geometry for catching the echo."
As the ISS raced through the radar beam at 17,000 mph, its velocity vector rotated with respect to the transmitter below. That's why the echo sounds like the frequency-shifting whistle of a passing train. It's the Doppler effect, working in space the same way it does on Earth.
The space station will be making more passes through the radar beam in the days ahead. Next up: Sept. 24 @ 2142 UT (1642 CDT). Tune in to SpaceWeather Radio for live echoes.

UPDATED: Sept. 2010 Northern Lights Gallery
[previous Septembers: 2009, 2008, 2007, 2006, 2005, 2004, 2002, 2001, 2000]

Near Earth Asteroids

Potentially Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time.

On September 20, 2010 there were 1145 potentially hazardous asteroids.

Recent & Upcoming Earth-asteroid encounters:

Asteroid	Date(UT)	Miss Distance	Mag.	Size
2010 RF12	Sep 8	0.2 LD	28	9 m
2010 RJ53	Sep 9	8 LD	24	69 m
2010 RS80	Sep 9	2.2 LD	26	23 m
2010 RM82	Sep 10	2.2 LD	26	31 m
2009 SH2	Sep 30	7.1 LD	25	45 m
1998 UO1	Oct 1	32.1 LD	17	2.1 km
2005 GE59	Oct 1	77 LD	18	1.1 km
2001 WN5	Oct 10	41.8 LD	18	1.0 km
1999 VO6	Oct 14	34.3 LD	17	1.8 km
1998 TU3	Oct 17	69.1 LD	15	5.3 km
1998 MQ	Oct 23	77.7 LD	17	1.9 km
2007 RU17	Oct 29	40.6 LD	18	1.0 km
2003 UV11	Oct 30	5 LD	19	595 m
3838 Epona	Nov 7	76.8 LD	16	3.4 km
2005 QY151	Nov 16	77.7 LD	18	1.3 km
2008 KT	Nov 23	5.6 LD	28	10 m
2002 EZ16	Nov 30	73.9 LD	18	1.0 km
2000 JH5	Dec 7	47 LD	17	1.5 km

Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach.

LA NASA.