Sunday, October 1, 2017

Monthly Night Sky Report: October 2017

The spooky month of October is here.  With it, the days become shorter and the nights longer, as well as much cooler weather, typically.  The longer nights are great for stargazing, but the colder temperatures make it more difficult for observers to spend the night under the stars.

Astronomically, October will bring a decent meteor shower without interference from the Moon, a planet reaching opposition, a dim comet, an asteroid that can be viewed through binoculars, and even a disappearing star!

Beginning with the planets, as usual, Mercury will not be visible until months end, as it will reach a point in its orbit called superior conjunction.  This places the planet behind the Sun from our point of view on Earth.  When Mercury returns, it can be found in the southwestern sky approximately 30 minutes after the Sun sinks below the horizon.  I hope that you will be able to catch a glimpse when Mercury returns.

Venus will continue to impress the early-risers with its luminosity.  It can be found the eastern, morning sky and will remain visible until shortly before sunrise.  By the 8th, Venus will pass from the constellation of Leo the Lion into the constellation of Virgo.  

Mars will join Venus in the morning sky.  On the first morning of the month, Mars and Venus will appear very close in our sky.  In fact, this will be closest they have been since 1995.  So be sure to look if you have a clear sky.  Mars will follow Venus from Leo into Virgo four days after Venus, on the 12th.  The Moon will join these two planets on the 17th, creating quite a sight.

If you want to see Jupiter this month, you will have to be quick.  After the first week, Jupiter will be below our horizon before it is dark enough to see it.  It can be found in the west about 30 minutes after sunset, but that time will shorten as the opening week of October progresses.  Jupiter will pass behind the Sun on the 26th from our vantage point.  Stay tuned for its reemergence in early November.

Saturn's earthly companion, Cassini, dived below the clouds mid-month last month, ending its 20-year mission.  But don't let that stop you from giving Saturn your attention this month.  If you have a telescope, or know someone that does, be sure to take a look at this ringed planet mid-month while its ring system is at its maximum tilt for Earth.  The last time the rings were at this position was 14 years ago and it won't happen again for another 15 years.  This tilt of the rings offers excellent views.

The planet that reaches opposition this month is Uranus.  This happens on the 19th, making it visible all night.  This will be the brightest the planet will shine for earth-bound observers.  If you are able to get to a dark sky, you should be able to see it with unaided eyes.  Using binoculars and a telescope will greatly enhance your views as well as the blue-green color of Uranus.

Neptune can be found in the southeastern sky after sunset.  However, you will need binoculars or a telescope to spot this planet.  It will appear blue-gray in color and should be easy to tell apart from the background stars in your field of view.  For those in the northeastern United States or eastern Canada, you can view a rare event if you have a 6 inch or larger telescope.  On the 5th, Triton, a moon of Neptune, will pass directly in front of the planet so be sure to look if you have a clear sky.  On this same night, Triton will pass in front of a star, blocking it from our view.  This star has an impressive name of 4U 410-143659.  As mentioned, you will need a telescope to view this event.

The Orionid meteor shower will peak on the 21st with a maximum rate of 20 meteors per hour.  These meteors will appear to radiate from the constellation of Orion the Hunter so be sure this constellation is in clear view when you go out to watch.  The Moon will not interfere with this shower like it has for other showers earlier this year.

If you are able to get to dark sky between the 17th and November 2nd, try to see if you can spot the zodiacal light.  It will be visible in the eastern morning sky before sunrise.  This light is caused by sunlight reflecting off of dust particles, called cosmic dust, in the solar system.  While you can see this light year round if you can get away from all light pollution, the best time is close to the spring and autumn equinox.

Comet PANSTARRS (C/2015 ER61) can be found slightly below the Pleiades star cluster during the first night of October.  However, the Moon will interfere with views until after the 10th.  Unfortunately, you will need a 4-inch or larger telescope to view this comet.

The asteroid, Iris, will be visible this month as well.  If you are able to get to dark sky, you should be able to spot it with unaided eyes, but even if you live in the suburbs, you can still see it with a pair of binoculars.  It can be found in the constellation of Aries the Ram near its brightest star, Hamal.  This constellation can be found high in the eastern sky by mid-evening.  Iris will reach opposition on the 29th, causing it to shine slightly brighter.

Here is the breakdown for October.

October 05:  Mars and Venus make their closest approach since 1995 in the morning sky.
October 05:  Triton transits Neptune and makes a star "disappear".
October 17:  Mars, Venus, and the Moon appear close together.
October 19:  New Moon; Uranus at opposition.
October 21:  Orionid meteor shower peaks.
October 29:  Asteroid Iris is at opposition.  Look in Aries.

October is another quiet month astronomically speaking as far as history goes.  It is still an impressive month nonetheless as you will hopefully see.

Starting off the history lesson, on October 4, 1957, the Soviet Union was the first to launch a man-made satellite.  You have probably heard its name before, but perhaps did not realize it was the first satellite ever launched.  The launch of this satellite, designated as Sputnik 1, which means "fellow traveler", started the space age, as well as the space race between the United States and the Soviet Union.  The Sputnik program consisted of the first 5 missions which involved sending plants and animals into orbit to see what effects were caused by being in space.

Next on my list is another first by the Soviet Union.  On October 7, 1959 the space probe Luna 3 returned the first ever images of the far side of the Moon.  This was the first time that any human had seen the far side since the Moon is tidally locked with the Earth, meaning that only one side of the Moon ever faces the Earth.  These images showed that the far side is heavily cratered compared to the side that we see.  This shows astronomers that the Moon is less active volcanically on the far side than it was on the near side during the formation.

Now get outside and look up!

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