SDO observes Earth, lunar transits in same day

Mar 11, 2013 by Karen C. Fox
Left: The view of the sun is partially obscured by Earth as seen by NASA's Solar Dynamics Observatory on Mar. 11, 2013, at 2:20 a.m. EDT. Credit: NASA/SDO Right: This image from NASA's Solar Dynamics Observatory on Mar. 11, 2013, at 8:00 a.m. EDT, shows the moon crossing in front of the sun. Credit: NASA/SDO

On March 2, 2013, NASA's Solar Dynamics Observatory (SDO) entered its semiannual eclipse season, a period of three weeks when Earth blocks its view of the sun for a period of time each day. On March 11, however, SDO was treated to two transits. Earth blocked SDO's view of the sun from about 2:15 to 3:45 a.m. EDT. Later in the same day, from around 7:30 to 8:45 a.m. EDT, the moon moved in front of the sun for a partial eclipse.

When Earth blocks the sun, the boundaries of Earth's shadow appear fuzzy, since can see some light from the sun coming through Earth's atmosphere. The line of Earth appears almost straight, since Earth—from SDO's point of view—is so large compared to the sun.

The eclipse caused by the moon looks far different. Since the moon has no atmosphere, its curved shape can be seen clearly, and the line of its shadow is crisp and clean. Any spacecraft observing the sun from an orbit around Earth has to contend with such eclipses, but SDO's orbit is designed to minimize them as much as possible, with only two three-week eclipse seasons each year. The 2013 spring season continues until March 26. The fall season will begin on Sept. 2.

Explore further: NKorea launch pad expansion 'nearing completion'

add to favorites email to friend print save as pdf

Related Stories

SDO enters its semiannual eclipse season

Sep 07, 2012

(Phys.org)—Twice a year, for three weeks near the equinox, NASA's Solar Dynamics Observatory (SDO) moves into its eclipse season—a time when Earth blocks its view of the sun for a period of time each ...

SDO's crazy-looking Sun due to syzygy

Apr 04, 2011

It looks like something is eating the Sun in recent pictures from the Solar Dynamics Observatory — and in recent SDO videos, the Sun suddenly disappears! What is going on? Could it be aliens, Planet X, ...

Getting Solar Dynamic Observatory into focus

Oct 06, 2012

From Sept. 6 to Sept. 29, 2012, NASA's Solar Dynamic Observatory (SDO) moved into its semi-annual eclipse season, a time when Earth blocks the telescope's view of the sun for a period of time each day. Scientists ...

New lunar eclipse video released

Jun 09, 2011

(PhysOrg.com) -- In anticipation of the upcoming lunar eclipse later this month, NASA has released a new video that shows how lunar eclipses work.

Southern hemisphere to glimpse year's last solar eclipse

Nov 24, 2011

The tip of South Africa, Tasmania and most of New Zealand will -- weather permitting -- enjoy a partial eclipse of the Sun on Friday although the handful of hardy scientists in Antarctica will get the best view, according ...

LRO observes final lunar eclipse of the year

Dec 09, 2011

(PhysOrg.com) -- Orbiting 31 miles above the lunar surface, NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft will get a "front-row seat" to the total lunar eclipse on Dec. 10, 2011.

Recommended for you

Amazing raw Cassini images from this week

4 hours ago

When Saturn is at its closest to Earth, it's three-quarters of a billion miles away—or more than a billion kilometers! That makes these raw images from the ringed planet all the more remarkable.

Europe launches two navigation satellites

4 hours ago

Two satellites for Europe's rival to GPS were lifted into space on Friday to boost the Galileo constellation to six orbiters of a final 30, the European Space Agency (ESA) said.

SpaceX gets 10-year tax exemption for Texas site

5 hours ago

Cameron County commissioners have agreed to waive 10 years of county taxes as part of an agreement bringing the world's first commercial site for orbital rocket launches to the southernmost tip of Texas.

Voyager map details Neptune's strange moon Triton

7 hours ago

(Phys.org) —NASA's Voyager 2 spacecraft gave humanity its first close-up look at Neptune and its moon Triton in the summer of 1989. Like an old film, Voyager's historic footage of Triton has been "restored" ...

How the sun caused an aurora this week

8 hours ago

On the evening of Aug. 20, 2014, the International Space Station was flying past North America when it flew over the dazzling, green blue lights of an aurora. On board, astronaut Reid Wiseman captured this ...

User comments : 0