Why settle for dusty ol' Mayan calendars and 12/12/12 apocalyptic visions,
when 2012 has been offering up so many stellar—and planetary—sightings?
We Earthlings have already been treated to nice meteor showers as well
as a magnificent supermoon, and this weekend brings an annular solar
eclipse.
That's not even the best treat:
Venus will be ambling between Earth and the sun in a rare (though
non-earth-shattering) planetary alignment. Sure, the event might look
like a black pimple floating across the face of the sun, but this
celestial rarity once guided adventurous astronomers in their quest to
determine the size of the solar system and yielded the first-ever
global scientific collaboration. Don't blink—Venus doesn't cross our
path again until December 2117.
An annular solar eclipse and that ring of fire:
A solar eclipse happens this Sunday, except for the Eastern seaboard
(sorry). It's an "annular" eclipse rather than a total one, which means
the sun's edges peek out from behind the moon, creating the illusion of
a ring of fire. (The word "annular" comes from the Latin word for
ring.) The lower 48 states will have to wait until Aug. 17, 2017, for a
total shutout. This weekend's eclipse
begins at dawn in southern China. It then sweeps across the Pacific
Ocean, passing south of Alaska, and makes landfall on the Pacific coast
near the California-Oregon border. It ends near Lubbock, Texas, at
sunset. Partial phases of this eclipse will be visible over most of
western North America. (May 9, Space.com)
Those of you in the annular path should head to higher ground (avoiding
clouds and light pollution) and put solar filters either over your eyes
or on your equipment. Thirty-three national parks will be hosting solar gatherings. Lucky Coloradans get to hang out for free at the University of Colorado at Boulder's Folsom stadium, starting 5:30 p.m. local time, thanks to the Fiske Planetarium.
What kind of solar glasses to get:
Designer sunglasses don't cut it. At this late date, check telescope
stores or call your local planetarium. No. 14 welder's glass, carried
in specialty welding stores, works too. Don't forget solar filters for
your camera equipment. Then there's the cardboard method:
The
safest and simplest technique is perhaps to watch the eclipse
indirectly with the solar projection method. Use your telescope, or one
side of your binoculars, to project a magnified image of the sun's disk
onto a shaded white piece of cardboard.The image on the cardboard will
be safe to view and photograph. But make sure to cover the telescope's
finder scope or the unused half of the binoculars, and don't let
anybody look through them. (May 9, Space.com)
If you don't buy binoculars for this weekend, you may want to consider ordering a pair for the transit of Venus.Measuring the solar system with the transit of Venus: Yes, there's an app.
With just the tap of a finger on a screen, people can do in hours what
18th-century scientists needed years to do: measure the solar system.
This year's transit of Venus—the second of a pair—begins on the evening
of June 5 for North Americans. Our previous glimpse was in June 2004,
and before that, back in the 19th century. An explanation of this
planetary alignment:Mercury and Venus are the only planets closer to the Sun than Earth,
both moving faster in their orbits and passing us regularly. But rather
than crossing directly between us and the Sun, these planets are
usually slightly above or below the Sun as we see them. When they line
up just right we see the round, black silhouette of the planet slowly
crossing the Sun, an even referred to as a "transit." Mercury transits
the Sun 13 or 14 times each century. But Venus transits happen in
pairs—two transits eight years apart—with more than 100 years between
each pair. (Transit of Venus, Astronomers Without Borders)
How to see the transit of Venus: Astronomy Without Borders will stream a webcast from Mount Wilson Observatory. See above about solar glasses.
Measuring the solar system the old-fashioned way:
In 1761 and 1769, obsessed stargazers undertook glorious, and sometimes
fatal, journeys, in an orchestrated effort that took 45 years to
coordinate.
In
1716, British astronomer Edmond Halley had called upon scientists to
unite in a project spanning the entire globe. He predicted that on June
6, 1761, Venus would traverse the burning disc of the sun for about six
hours.At a time when it took six days
to travel from London to Newcastle, dozens of them travelled to remote
outposts of the world to observe the phenomenon, laden with clocks,
huge telescopes and other instruments.Many risked their lives. With the Seven Years' War [1756-63] tearing Europe apart, they were even sent into war zones. (May 12, The Daily Mail)
Most were not swashbuckling men by any measure, but they risked
traveling with instruments and rum, barely surviving shipwrecks and
warship attacks. In 1761 Venus didn't quite cooperate and messed up the
calculations. The second transit—on June 3, 1769—saw more success.
Sharing the information took years, but the calculated distance between
Earth and the sun wasn't far off the 92,960,000 miles that scientists
agree on today.
More to come: Put this on your night calendar or monitor: Sea and Sky.
Marshall Space Flight Center astronomer Mitzi Adams recommends the
Perseids in August, which always has very bright meteors. "The
conjunction of Venus and Saturn in November (27) should be pretty
spectacular and complements the conjunction of Venus and Jupiter that
occurred in March," she told.
