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[Lively music]

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What's Up for April?

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Conjunction junction

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and a hidden surprise
 in the Big Dipper.

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At the beginning of April,
 Venus, Mars and Saturn

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form a trio in the southeast
 before sunrise, with Saturn

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appearing to move steadily
 toward Mars each day.

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On April 1st, they're a couple
 of finger widths apart.

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And by the fourth, Saturn

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and Mars are separated by less
than the width of the full moon.

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Saturn then moves on increasing
 its separation from Mars

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each day as a new addition to
the morning sky makes its debut.

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By mid-month,
 Jupiter is starting to rise

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in the pre-dawn hour.

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Making for a quartet of planets

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strung out in a line
 across the morning sky.

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Heading into the last week of
 April, Jupiter will be high

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enough above the
 horizon in the

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before sunrise to make it
 more easily observed.

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The two brightest
 planets in the sky,

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Venus and Jupiter, are headed

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for their own ultra-close
 conjunction on April 30th,

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similar to the meetup of Mars
and Saturn earlier in the month.

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In fact, they approach to
 about the same distance.

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Of course, the planets
are actually far apart in space

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and only appear to move closer
 or farther apart in the sky

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as our view of them

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across the solar system
 changes from month to month.

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If you recall

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the grand conjunction of Jupiter
and Saturn at the end of 2020,

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these conjunctions
are not quite as close as that,

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but still really impressive

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and they'll make for thrilling
 sights in the morning sky.

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So definitely try to
 catch them if you can.

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Whether you call it
 the Big Dipper

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or Ursa Major or the Plough,

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it's probably the

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most familiar pattern of bright
 stars in the northern sky.

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The Big Dipper
 is a really useful reference

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for finding your way
 around the sky,

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but it also contains
 a hidden surprise.

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One of its stars
 is really two...

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Or, actually six...

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Let's break that down.

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What looks on first glance
 like a single

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bright star here, midway along
 the Dipper's handle, is on

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closer inspection,
a double star Mizar and Alcor.

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Next time you have a chance,

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try to see

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if you can perceive them
as two stars with your own eyes.

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Once you give it a try,

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then grab binoculars
 if you have them,

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which will easily
 show them as separate stars.

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The two star systems are around

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a light year apart

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and are located
 80 light years away

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from our solar system,
 with Alcor taking

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just shy of a million years to
complete an orbit around Mizar.

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Now, lots of stars
 are bound together

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by gravity in small groups,

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especially in pairs or binaries
 that orbit around each other.

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But usually it takes a telescope
 to be able to see them

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as separate stars.

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Mizar and Alcor are a rare
 example of a double star

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that you can see as a pair
without the aid of a telescope.

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But it gets more interesting.

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Although they appear as a close
 pair of two stars,

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they are, in fact six.

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Alcor is a binary
pair of two stars, while Mizar

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is actually four stars:
 two pairs of binaries.

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So find the unusual
"double" stars Mizar and Alcor

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in the Big Dipper in April,
where what at first appears as

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one star is in reality
 a six-star system.

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Here are the phases
 of the Moon for April.

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Stay up to date
 with all of NASA's missions

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to explore the solar system
 and beyond at NASA.gov.

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I'm Preston Dyches from NASA's
 Jet Propulsion Laboratory