Transcript 20061108_Mercury_ho

Transit of Mercury
November 8, 2006
Beginning of transit:
2:12pm
Sunset: 5:00pm
End of transit: 5:10pm
Time sequence
of Mercury
in
transit
on
May 7,
2003
Mercury will look
perfectly round and about
the same size as a small
sunspot.
path
today
Mercury will appear to be
1/194 of the Sun’s
diameter. YOU CANNOT
SEE IT WITH YOUR
Image copyright Dominique Dierick
NAKED EYE! True ratio of Mercury’s and Sun’s diameter: 1/286.
Close-up of 2003 transit
Sun
Distance from Us
Diameter
1 AU
1.4 x 109 m
(93,000,000 mi)
(860,000 m
Mercury 0.69 AU (today)
(64,000,000 mi)
Image by Royal Swedish Academy
of Sciences
Earth
You’re standing
on it!
4.9 x 106 m
(3000 mi)
1.3 x 107 m
(8000 mi)
Mercury Facts
Mercury is the closest planet to the Sun.
Rotation period: 59 d
Atmosphere: none
Average day temp: 710 K (820o F)
Average night temp: 80 K (-320o F)
Orbital period: 88 days
Average distance from Sun: 0.39 AU
(36,000,000 mi)
Image by Mariner 10, NASA
Mercury’s orbit is the most elliptical of all the planets. Today, Mercury is
near perihelion, which means it is closest to the Sun. But, that makes it
farther from us!
Transit Facts
Close-up of Mercury’s surface,
seen by Mariner 10. It is
completely covered by craters.
Image by NASA/JPL/Northwestern U.
Transits of Mercury only occur
when the Sun, Mercury, and the
Earth are precisely lined up.
Since Mercury’s orbit is tilted
slightly, these alignments happen
rarely.
Transits of Mercury occur
approximately 13 times per century.
Next transit: May 9, 2016.
Last transit: May 7, 2003.