Saturday: Venus is one fist held upright and at arm’s length above due west at 9:30 p.m.
Sunday: Have you ever planned a vacation to a place because
it was supposedly the up-and-coming locale? Then, when the vacation time
finally arrives, you find out the place doesn’t live up to its billing? Over
the past decade, astronomers have revisited earlier findings about the
planetary system of the star Tau Ceti, one of our closest Sun-like star
neighbors at 12 light years away. It was originally thought to have four
planets classified as “super-Earths” with two of the planets being on the edge
of the habitable zone where the temperature is just right for having liquid
water on their surface. Time for a va-ca-tion! Well, not so fast. Astronomers
now think some of the planets may be too massive for complex life to form. And
the Tau Ceti system has ten times as much mass in dust and rocks as our own
solar system. On the plus side, if you want to save the Earth, the planet Tau
Ceti e is the place to go. In the book and movie Project Hail Mary, Ryland
Grace and the alien Rocky went there to discover how to kill the astrophage
that was consuming the Sun’s energy.
Tau Ceti is two fists above the southeast horizon at 4:30
a.m. For more information about the system, go to https://skyandtelescope.org/astronomy-news/four-exoplanets-may-orbit-nearby-sun-like-star/.
Monday: Mars is two fists above the eastern horizon at 4:30
a.m. Saturn is four and a half fists above the south-southeastern horizon at
this time.
Tuesday: Mizar is a well-known binary star in the
constellation Ursa Major. You can find it at the bend in the Big Dipper handle,
three fists above due northwest at midnight. Its name is Arabic for waistband.
Mizar has an optical double called Alcor, which is less than a pinky width away
and can easily be seen with the naked eye. Optical doubles are stars that are
close together in the sky but do not orbit a common center of mass as true
binary stars. Not wanting to deceive sky gazers who call Alcor and Mizar a
binary star, two stars that DO orbit a common center of mass, Mizar actually is
a binary. It was the first binary star system discovered using a telescope.
Mizar A and Mizar B are about 400 astronomical units apart from each other and
about 80 light years from Earth. 400 astronomical units is about 10 times the
distance between the Sun and Pluto.
Wednesday: Tonight’s full moon is in the constellation
Capricornus. The Wishram, Haida, and Tlingit people of the Pacific Northwest
call the July full moon the salmon moon. This is the time of year the salmon
return after spawning season.
Thursday: The Southern Delta Aquarid meteor shower peaks
early, early this morning at 4:00 a.m. In case you want to sleep through the
night, this shower has an extended peak into mid-August. Meteor showers are
named after the constellation from which the meteors appear to originate. These
meteors appear to come from a point in Aquarius near the star Delta Aquarii,
also known as Skat. This point is about two and a half fists above the southern
horizon at 4:00 a.m. The moon is close to full, obscuring the dimmer meteors.
For more information about this year’s shower, go to https://earthsky.org/?p=159138.
Meteors are tiny rocks that hit the Earth and burn up in the atmosphere.
Friday: The Perseid meteor shower peaks in a week and a
half. But there will be an increased number of meteors over the next two weeks.
If the Moon is out when you want to look, position yourself so you are blocked
from the Moon’s light. The meteors appear to come from a point just below the W
of the constellation Cassiopeia. This point is about two and a half fists above
the northeast horizon at 11:00 p.m. By dawn, this point is about seven fists
above the northeast horizon. If you fall asleep or forget to set your alarm,
you will be able to observe this shower from about 11:00 p.m. to dawn for the
next two weeks in about the same location in the sky.
The Perseid shower is one of the longest lasting showers.
For tips about optimizing your viewing this year, go to https://earthsky.org/?p=165416 These
meteors are sand to pea-sized bits of rock that fell from Comet Swift-Tuttle.
They travel about 40 miles per second as they collide with the Earth and burn
up in the atmosphere.
The positional information in this column about stars and
planets is typically accurate for the entire week. For up-to-date information
about the night sky, go to https://nightsky.jpl.nasa.gov/planner.cfm.
All times are Pacific Time unless noted.
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