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♪

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What's Up for March?

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The moon hides red
star Aldebaran

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and crescents dazzle after dusk.

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Hello and welcome. I'm
Jane Houston Jones from

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NASA's Jet Propulsion Laboratory
in Pasadena, California.

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On March 4 the
first quarter moon

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passes between Earth
and the star Aldebaran,

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temporarily blocking
our view of the star.

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This is called an occultation.

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The occultation begins and
concludes at different times,

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depending on where you
are when you view it.

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The event should be easy to
see from most of the U.S.,

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Mexico, most of Central
America, the Western Caribbean

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and Bermuda.

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Observers along a
narrow path from

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Vancouver, British Columbia, to
Hartford, Connecticut,

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will see the moon
“graze” the star.

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The star will disappear
and reappear repeatedly

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as hills and valleys on the moon

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alternately obscure
and reveal it.

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[Whoosh]

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As seen from Earth, both
Mercury and Venus

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have phases like our moon.

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That's because they circle the
sun inside Earth's orbit.

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Planets that orbit between Earth
and the sun are known as

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inner or inferior planets.

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Inferior planets can never
be at “opposition,”

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which is when the
planet and the sun are on

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opposite sides of Earth.

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But inferior planets can
be at “conjunction,”

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which is when a planet,
the sun and Earth

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are all in a straight line.

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Conjunction can happen once
when the planet is on

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the opposite side of
the sun from Earth

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and again when it's on the same
side of the sun as Earth.

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When a planet is on the opposite
side of the sun from Earth,

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we say it is at
“superior conjunction.”

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As the planet moves
out from behind the sun

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and gets closer to Earth,

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we see less and less
of the lit side.

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We see phases, similar to
our moon's phases.

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Mercury is at superior
conjunction on March 6.

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A few weeks later, the planet
emerges from behind the sun

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and we can once
again observe it.

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By the end of March we'll
see a last-quarter Mercury.

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On April 20 Mercury reaches
“inferior conjunction.”

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Brilliant Venus is
also racing toward

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its own inferior
conjunction on March 25.

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Watch its crescent
get thinner and thinner

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as the planet's size
appears larger and larger,

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because it is getting
closer to Earth.

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[Whoosh]

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Finally, look for Jupiter
to rise in the East.

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It will be visible
all month long

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from late evening until dawn.

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You can catch up on
solar system missions

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and all of NASA's missions
at www.nasa.gov