The comet PanSTARRS, C / 2017 S3 unexpectedly brightened to about 8th brightness. It's waiting for your riflescope or maybe even a pair of binoculars in the northeastern sky before dawn. See Bob King's Articles and Finder Charts: PanSTARRS Comet, Rocket of Breakout, Goes Green
Friday, July 20
• The burgeoning moon that rises above Jupiter seems to shine over Jupiter this evening, as shown here. Left of Jupiter by only 2 ° is the broad binocular binary Alpha Librae, Magnitudes 2.8 and 5.1.
The Moon is 1.3 light-seconds away from us, and Jupiter is 44 light-minutes in its background. The two stars of Alpha Librae are 77 light years behind them.
Saturday, July 21
• Now Jupiter and Alpha Librae are shining in the lower right of the moon. To the lower left side of the moon is Antares, scattered with other stars of the upper Scorpius.
Sunday, July 22
• The moon shines tonight on Antares and the head of Scorpius. Bright Vega approaches the zenith from the east, and Arcturus descends the western side of the sky.
Monday, July 23
• Saturn is shining tonight, as shown here, at the bottom left of the Gibbo Moon. The moon and Saturn form a not quite equilateral triangle with the cat's eyes, an unequal pair of stars in the tail of Scorpius far below. This triangle rises higher and rotates clockwise when the night gets too late.
The cat's eyes are inclined at an angle; The cat leans his head and winks. A line through them points west (right) almost fist-wide toward Mu Scorpii – a much tighter pair known as the small cat's eyes. Can you dissolve Mu without binoculars? It is difficult!
Tuesday, July 24
• The moon shines tonight with Saturn as shown here. Saturn, the farthest bright planet, is 3420 times farther and 35 times as wide.
Wednesday, July 25
• The almost full moon shines between Saturn, about a fist at arm's length to its right, and bright Mars about two fists to the moon below left (for evening in North America)
Thursday, July 26
• Mars is in opposition tonight, facing the sun, as seen from Earth. It will actually be closest to Earth in four days from now on the night of the 30th. But really, the difference between now and then is so tiny that it can not be detected anymore. Have fun!
Friday, July 27
• Full Moon (exactly at 4:20 pm EDT). Full Moon is an opposition moon, so it shines with the brilliant Mars, who is only one day behind his resistance.
Mars is 143 times farther away from us than the Moon (and twice as large). It is covered with rusty brown dust compared to the dark gray dust of the moon. Yes, they look orange and white in our night sky. But the only reason is that they are brilliantly lit by direct sunlight, while the rest of the nocturnal scenery around us, to which our eyes adjust, is much darker.
Saturday, July 28
• Now the moon shines further to the sky to the left of Mars after getting up.
Want to become a better astronomer? Explore the way through the constellations! They are the key to finding everything that is ever weaker with binoculars or telescopes.
This is an outdoor hobby for nature. For an easy-to-use constellation guide that covers the entire evening sky, use the large monthly map in the middle of each issue of Sky & Telescope the indispensable guide to astronomy.
If you have a telescope to use it, you will need a detailed, large-scale sky chart (charts). The base standard is the Pocket Sky Atlas (either in the original or jumbo edition), which shows stars up to a magnitude of 7.6.
Next follows the larger and deeper Sky Atlas 2000.0 drawing stars to magnitude 8.5; almost three times as many. The next, as you know it, is the even larger Interstellarum Atlas (stars to magnitude 9.5) and Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky diagrams with a telescope.
You'll also need a good deep-sky guidebook, such as Sue French's Deep-Sky Wonders collection (which includes own charts), Sky Atlas 2000.0 Companion by Strong and Sinnott or the larger Night Sky Observer's Guide by Kepple and Sanner .
Can a computer telescope replace cards? Not for beginners, I do not think, and not for mounts and tripods that are not mechanically high quality (so heavy and expensive). And as Terence Dickinson and Alan Dyer say in their Backyard Astronomers Guide "A full appreciation of the universe can not come without the ability to find things in the sky and understand how Heaven works." This knowledge comes only by passing under the stars with star cards in their hands. "
This week's Planet Roundup
Mercury is lost in the afterglow of the sunset.
Venus (magnitude -4.2, in eastern Leo) glows brightly in the west dusk, a little lower each week. It's about the end of dusk now. In a telescope, Venus is a Gibbous disk, 19 arc seconds high and 61% sunlit
Mars is the "star" planet of summer – and he'll be in opposition by the end of this week! It is a fire stove that flames like nothing else in the late evening. At a magnitude of -2.7 per -2.8, it is half a magnitude brighter than Jupiter. And its color gives it extra drama.
Spot Mars appears in the southeast just before dawn. After dark it rises higher and shifts to the south, a strange anomaly like no celestial object you normally see. Mars is highest in the south, in the best telescope view, around 1 o'clock in the summer, although it has a southern declination (-26 °) in southern Capricornus
Mars is almost closest, largest and brightest. It is now 23 to 24 arc seconds in diameter, almost at the peak size of 24.3 arc seconds, it will be maintained for about a week at its next approach on the night of July 30 to 30.
And a bit of good news for telescope observers: The dust that still covers the globe has started to thin a little, allowing for faint, low-contrast views of some dark Mars surface features. Observers are worried that dust is setting itself up as a Martian opposition approach.
Can you identify any marks? For a Mars map that shows which features point to Earth at your time and date, use our Mars Profiler.
Jupiter (magnitude -2.2, in Libra) glows in the south-southwest at dusk. It is about 20 ° to the right or lower right between Spica, and the head of Scorpius about 20 ° to the left. Catch Jupiter with your riflescope in the late twilight, before it gets deep.
Saturn (magnitude +0.1, above the Sagittarius Teapot) glows in the south after dark. It is about 30 ° on the top right of much brighter Mars.
Uranus (magnitude 5.8, on the border between Aries and Pisces) and Neptune (magnitude 7.8, in Aquarius) are well placed southeast and south respectively in the hour before first morning light. Findings for Uranus and Neptune
All descriptions referring to your horizon – including the words top, bottom, right, and left – are written for the middle northern latitudes of the world. Descriptions that also depend on the length (mainly lunar positions) are for North America.
Eastern Daylight Time (EDT) is the universal time (also called UT, UTC, GMT, or Z time) minus 4 hours
"Remember, to the Get up stars and not at your feet, try to understand what you see and wonder what makes the universe so curious. "
Stephen Hawking, 1942-2018
"The dangers of not thinking clearly are now much greater than ever before, it's not that there's anything new in our way of thinking there is this gullible and confused thinking can be far more lethal than ever before. "
– Carl Sagan, 1996
" Objective reality exists, facts are often determinable, vaccines save lives. Carbon dioxide heats the globe Bacteria evolve to prevent antibiotics because evolution Science and reason are not political conspiracies So we determine facts The survival of civilization depends on our ability and willingness to do so. "
– Alan MacRobert, Your Editor of Sky at A Glance
"Facts are stubborn things."
– John Adams, 1770