Latest / Star Trails: From Backyard Astronomy to Cosmic Wonder / Spring Skies, a Solar Eclipse, and the Shadow of a Black Hole

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Spring Skies, a Solar Eclipse, and the Shadow of a Black Hole · Star Trails: From Backyard Astronomy to Cosmic Wonder

• 0:07
  Howdy Star Gazers, and welcome to this episode
• 0:10
  of Star Trails. I'm Drew, and I'll be your guide
• 0:13
  to the night sky for the week starting March
• 0:16
  the 23rd through the 29th. This week we have
• 0:20
  a waning crescent moon, a lineup of bright planets,
• 0:24
  and an upcoming partial solar eclipse, though
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  it won't be visible from many places. We'll tour
• 0:31
  through the spring constellations Virgo and Cancer,
• 0:35
  and we'll examine how the first image of a black
• 0:38
  hole was created using a planet -sized telescope.
• 0:43
  So, grab a comfortable spot under the night sky
• 0:45
  and let's get started. The moon starts this week
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  in its waning crescent phase, meaning it's getting
• 0:53
  smaller each night as it approaches the new moon
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  on March 29th. If you're up before dawn, look
• 1:00
  for a thin sliver of moonlight in the eastern
• 1:03
  sky, especially earlier in the week. With less
• 1:07
  moonlight washing out the sky, this is the perfect
• 1:10
  time to catch a glimpse of faint galaxies, nebula,
• 1:14
  and star clusters. On March 29th, the new moon
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  means the moon will be completely invisible,
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  offering an ideal night for stargazing. Venus,
• 1:25
  now the morning star, is beginning to rise in
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  the pre -dawn eastern sky. If you're an early
• 1:32
  riser, watch for Venus low on the horizon just
• 1:35
  before sunrise. Mars will be visible after sunset,
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  hanging in the sky for more than nine hours into
• 1:42
  the late evening. With its reddish hue, it's
• 1:45
  easy to spot in Gemini, near the twin stars Castor
• 1:49
  and Pollux. Jupiter is still one of the brightest
• 1:53
  objects in the night sky, best seen just after
• 1:57
  sunset. It's fairly high in the western sky,
• 2:00
  hanging out in Taurus. As we look towards April,
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  let's take a moment to spotlight two constellations
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  that signal the arrival of spring, Virgo and
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  Cancer. Both have unique characteristics and
• 2:19
  house some stunning deep sky objects that are
• 2:22
  worth exploring. Virgo, the maiden of the skies,
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  is one of the largest constellations and plays
• 2:29
  a major role in spring stargazing. It's also
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  one of the 12 zodiac constellations and is often
• 2:37
  associated with harvest and fertility myths across
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  different cultures. Virgo is best identified
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  by its brightest star, Spica, a brilliant blue
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  -white star that sits about 260 light years away
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  from Earth. Spica is a binary star system, two
• 2:57
  stars locked in a close dance around each other.
• 3:01
  To locate Virgo, draw an imaginary arc from the
• 3:05
  handle of the Big Dipper to Arcturus in Boötes,
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  and then extend it downward to Spica. This is
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  the famous stargazing guide, arc to Arcturus,
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  then speed on to Spica. Virgo is home to some
• 3:21
  of the richest galaxy fields in the night sky.
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  Some of the most famous objects include the Virgo
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  Cluster of Galaxies. This enormous collection
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  of galaxies is about 50 million light years away
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  and can be found between Leo and Virgo. The cluster
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  contains more than 1 ,300 spiral, elliptical,
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  and irregular galaxies, many of which can be
• 3:46
  seen with a medium -sized telescope. Messier
• 3:50
  87 is one of the brightest galaxies in the Virgo
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  cluster. M87 is a giant elliptical galaxy and
• 3:58
  is famous for being the home of the first black
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  hole ever imaged back in 2019. We'll talk about
• 4:06
  how that image was created in the second half
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  of the show. If you have a telescope, you might
• 4:11
  just catch a glimpse of its faint glowing core.
• 4:15
  The Sombrero Galaxy M104 is an edge -on spiral
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  galaxy that looks like a Sombrero hat, with a
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  bright central bulge and a dust lane cutting
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  across it. Located just outside the Virgo cluster,
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  M104 is 28 million light -years away, and shines
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  at a magnitude of 8, making it a great target
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  for small telescopes. Now let's shift to a constellation
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  that doesn't always get as much love, Cancer
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  the Crab. Cancer is one of the faintest zodiac
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  constellations, but it holds some amazing deep
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  sky objects. Cancer sits between Gemini and Leo.
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  Since it lacks bright stars, the best way to
• 5:02
  locate it is by looking between the bright twin
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  stars of Castor and Pollux, and the star Regulus
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  in Leo. Once you find this faint region, you're
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  looking at Cancer. Cancer is home to one of the
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  best open star clusters in the entire night sky,
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  the Beehive cluster M44. This swarm of stars
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  is one of the brightest and closest open star
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  clusters to Earth, just 577 light -years away.
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  It contains more than a thousand stars, many
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  of which are similar to our Sun, making it one
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  of the most rewarding sites for backyard astronomers.
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  In dark skies, it's visible to the naked eye,
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  appearing as a hazy patch. A pair of binoculars
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  will reveal dozens of bright stars swarming together,
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  just like bees in a hive. Telescope owners may
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  want to chase down M67, one of the oldest open
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  clusters. Perhaps even more intriguing than the
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  beehive cluster, M67 is estimated to be 4 billion
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  years old, meaning some of its stars are nearly
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  as old as our Sun. It contains around 500 stars
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  and lies about 2 ,700 light years away. Astronomers
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  study it to understand how sun -like stars evolve
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  over time. M67 is visible in binoculars, although
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  a telescope will reveal more individual stars
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  packed into its core. A partial sunrise solar
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  eclipse is happening on March the 29th, but sadly
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  it's not visible for most of us here in the States.
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  A partial solar eclipse happens when the Moon
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  passes between the Earth and the Sun, but they
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  don't align perfectly. This results in the Moon
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  covering only a portion of the Sun's disk, taking
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  a characteristic bite out of the Sun. In the
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  northeastern United States and eastern Canada,
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  the eclipse will be visible at sunrise. For example,
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  in Hartford, Connecticut, the event starts around
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  6 .38 a .m. Eastern Daylight Time, reaches its
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  maximum at 6 .41, and concludes by 7 .07 a .m.
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  The best views in the U .S. will be in northeastern
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  Maine, where up to 85 % of the sun will be obscured
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  at sunrise. This eclipse will be observable across
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  much of Europe during the late morning. In London,
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  approximately 30 % of the Sun will be obscured
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  with the event occurring between 10 a .m. and
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  noon GMT, peaking around 11 a .m. On April 10,
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  2019, history was made when scientists released
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  the first -ever image of a black hole, located
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  in the center of the galaxy M87 in the Virgo
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  Cluster. This groundbreaking achievement was
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  the result of an international collaboration
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  known as the Event Horizon Telescope Project,
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  a network of radio telescopes around the world
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  working together to capture an object that by
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  its very nature, is invisible. A black hole is
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  a region of space where gravity is so intense
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  that nothing, not even light, can escape it.
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  Black holes form when massive stars reach the
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  end of their life cycles and collapse under their
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  own gravity. This collapse can result in a stellar
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  mass black hole, typically a few times the mass
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  of our sun. or over billions of years grow into
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  a supermassive black hole, such as that at the
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  center of a galaxy. Supermassive black holes,
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  like the one in M87, are millions or even billions
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  of times the mass of our sun. Scientists believe
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  they form over time, possibly from the merging
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  of smaller black holes and the accumulation of
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  vast amounts of matter. These cosmic giants exert
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  tremendous gravitational influence, shaping the
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  orbits of stars and affecting entire galaxies.
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  One of the defining features of a black hole
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  is the event horizon, the boundary beyond which
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  nothing can return. Any matter or light that
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  crosses this threshold is permanently lost to
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  the singularity, a point where gravity is thought
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  to become infinitely strong. Surrounding the
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  event horizon is an accretion disk, a swirling
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  superheated ring of gas and dust falling toward
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  the black hole. This glowing material is what
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  allows astronomers to detect and study black
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  holes, even though the black holes themselves
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  are invisible. The black hole that was imaged
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  lies at the heart of M87. a giant elliptical
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  galaxy in the Virgo cluster about 55 million
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  light -years away from Earth. This black hole
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  is a monster with a mass of 6 .5 billion times
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  that of our Sun. It was chosen as the target
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  of the Event Horizon telescope project because
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  it's relatively close, cosmically speaking, making
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  it one of the easiest supermassive black holes
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  to observe. Also, it has an enormous event horizon,
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  meaning it would cast a large shadow that could
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  be detected. It's surrounded by a bright accretion
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  disk, providing the perfect contrast to capture
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  the black hole's silhouette. The Event Horizon
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  Telescope isn't a single telescope, but a network
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  of eight radio telescopes positioned around the
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  world, from Chile to Hawaii, the U .S., Spain,
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  and Antarctica. By linking these telescopes together,
• 11:15
  astronomers effectively created a planet -sized
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  telescope using a technique called very -long
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  baseline interferometry. The final image, assembled
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  from petabytes of data, revealed the now famous
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  fiery ring, a circular glow of superheated gas
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  surrounding a dark central shadow, which is the
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  event horizon of the black hole. The image provided
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  direct evidence that black holes exist and behave
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  as predicted by Einstein's relativity. It confirmed
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  that black holes can be imaged and it gave scientists
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  insight into how matter behaves in extreme gravitational
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  environments. This image was only the beginning.
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  The EHT has since produced a similar image of
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  Sagittarius A, the black hole at the center of
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  our Milky Way. and continues refining its methods
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  to uncover even more secrets of the universe.
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  While you can't see this black hole from your
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  backyard, you can definitely see M87. And knowing
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  that a supermassive black hole is right in the
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  middle of it is a powerful idea to ponder. If
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  you found this episode helpful, let me know,
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  and feel free to send in your questions and observations.
• 12:39
  The easiest way to do that is by visiting our
• 12:41
  website, StarTrails .Show. This is also a great
• 12:46
  way to share the show with friends. Until next
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  time, keep looking up and exploring the night
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  sky. Clear skies everyone!