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[Energetic music]

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[Preston Dyches]
What's Up for April?

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Mercury rising,

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this month's Moon
and planet pairings

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and the Lyrid meteor shower.

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First up, on April 11th,
the planet Mercury, smallest

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and fastest
moving of the planets

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in our solar system,

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will reach its highest
and most visible

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in the evening sky for the year.

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Mercury is only
visible in the sky

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for a few weeks
every three to four months.

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The rest of the time it's
too close to the sun in the sky

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and is lost in its bright glare.

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And since the planet orbits
so close to the sun,

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it's always near the
sun in the sky.

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Appearing low near the horizon
for no more than an hour or two,

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either following sunset
or preceding sunrise.

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Some of Mercury's
fleeting appearances,

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known as “apparitions,”

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are better for
observing than others,

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for a combination of reasons
that have to do with

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how our view of the solar system
changes with the seasons,

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what hemisphere you're in,
and what phase

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the planet happens
to be showing us at the time.

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For this apparition,
in the Northern Hemisphere,

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the best viewing is April 3rd
through the 11th,

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as the planet appears
higher in the sky each evening.

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It quickly fades in brightness
after that, as the phase

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it shows us becomes an
increasingly slimmer crescent.

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Also on April 11th,
you'll find the planet

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Venus right next to
the Pleiades star cluster.

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The two will be close enough
to appear

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in the same field of view
through binoculars.

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This pairing makes for a fun
reminder that the night sky

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is kind of like a time machine.

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The farther out in space
you look, the farther back in

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time you're seeing.

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On that night you're seeing
light that left Venus about

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nine minutes earlier,

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whereas the light
of the Pleiades left

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those stars around
400 years ago.

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The latter
half of April

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includes some awesome close
approaches of the Moon

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with three of the bright
planets in the sky.

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On April 15th and 16th,
you'll find the crescent Moon

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rising with Saturn.

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Find them
low in the southeastern sky

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in the couple of hours
before sunrise.

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Then on the evening of the 23rd,
find the slim crescent Moon

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hanging just five degrees above
Venus in the west after sunset.

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And on April 25th,
the Moon finds its way over

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to Mars
high up in the west after dark.

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At this time,
around the 26th and 27th,

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the Moon will be at its
first quarter phase, meaning

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it appears as a “half-moon,”
high in the sky after dark.

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The first-quarter
Moon is a great time

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to pull out your binoculars
or telescope if you have them,

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as it's an ideal time
to observe the Moon's

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craters and mountains
along the terminator,

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the day/night boundary,
with ease.

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Lots of astronomy clubs plan

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public observing nights
around this time as well,

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and you can look
for events in your area

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with NASA's Night Sky Network.

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April brings
the annual Lyrid meteor shower.

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It's a medium-strength shower
that can produce up to 20

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meteors per hour at its peak,
under ideal conditions.

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The Lyrids peak this year
in the pre-dawn hours of April

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23rd, though,

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you should see a few
shooting stars

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on the morning before
and after the peak as well.

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Fortunately, the peak falls

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just a couple of days
after the new moon.

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That means the Moon
won't interfere

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with this year's Lyrids

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overwhelming fainter meteors
in the glow of moonlight.

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The Lyrids are named
for the constellation Lyra,

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which is near the point
in the sky where their meteors

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appear to come from,
called the radiant.

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They're one of the oldest
known meteor showers,

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with a first recorded sighting
in China some 2,700 years ago.

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They originate as dust particles
from a comet

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during its 400-year orbit
around the Sun.

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The Lyrids tend to produce
fast-moving meteors

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that lack persistent trails,

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but they can also produce

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the occasional bright meteor
called a fireball.

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To observe them,

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find a comfortable spot
away from bright city lights,

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get horizontal
and look straight up.

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You'll see the most meteors
by looking slightly away

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from the origin point, which is
near the bright star Vega.

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So here's wishing
you clear skies to catch a few

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shooting stars one April morning
when the forecast calls

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for light showers of comet dust
with a chance of fireballs.

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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

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and that's
What's Up for this month.