Category Archives: General Astronomy

Astronomical Events, General Astronomy, Solar System

Planets of the Month: DECEMBER, 2019

by Erich Karkoschka
Planets for December 2019

planet-of-the-month-mercury Mercury will be visible until December 19th, rising just after Mars (15 degrees below) before dawn.
planet-of-the-month-venus Venus is in the evening sky, getting higher and more obvious.
planet-of-the-month-moon New Moon will be at Christmas, last visible in the morning of the 24th and coming back in the evening sky on the 27th below Venus and the 28th right next to Venus, a beautiful pair.
planet-of-the-month-mars Mars rises before dawn in Libra, followed by Mercury 15 degrees below.
 planet-of-the-month-saturn Saturn is to the upper left of Venus in the evening sky until December 10 & 11, when Venus passes two degrees south of Saturn. At that time, Pluto is right next to both planets, but 15 million times fainter than Venus and not an easy target. After Christmas, Saturn will be too close to the Sun to be visible.
 planet-of-the-month-uranus Uranus is well placed in the evening for observers with binoculars or a telescope.
 planet-of-the-month-neptune Neptune is well placed in the evening for observers with binoculars or a telescope.
pluto Pluto is next to Venus & Saturn December 10 & 11 but is 15 million times fianter and not an easy target. The brightest minor planet, Vesta, is not too far from Uranus and only slightly fainter.
32 inch Cassegrain Project, General Astronomy, Star Parties

December 2019 Events

planets-of-the-month-right-column

We have two Tucson public observing events this month.

– Agua Caliente Park (NE Tucson) on December 21st:  CANCELLED
– Tucson Mountain Park Ironwood Picnic Area (SW Tucson) on December 28 from 6 – 8 pm. Follow the Facebook event for real-time updates.

Meteor Shower. The Geminids peak early morning on December 14th or late evening on the 14th. There will be a bright Moon in the sky very close to Gemini which will limit what you can see. If possible put the Moon to your back and look for meteors in the opposite direction.

General Astronomy, Solar System, Star Parties

Mercury Transit Across the Sun (November 11, 2019)

by Jim Knoll

Monday November 11, 2019 (Veterans Day). This is a school holiday and a work holiday for many. Don’t pass up this “seldom-in-a-lifetime event”. A Mercury Transit (passing in front of) will NOT be visible again in the U.S. until May 7, 2049. Transits occur only 13-14 times per century. A Mercury Transit is too small to see without a properly filtered solar telescope. When you observe a transit, you see a small black circle (the planet Mercury) moving across the Sun. This event is visible throughout the U.S. TAAA will have several solar telescopes to safely view the Transit at Brandi Fenton Memorial Park (3482 E River Rd, River & Alvernon) on November 11 from 7:30 – 11 am (Mercury mid-transit when it is crossing the middle of the Sun is at 8:20 am Tucson time).  Sunrise November 11 is 6:49 am and the Transit will already be underway. You can follow the Mercury Transit event on our Facebook page (facebook.com/tucsonastronomy) for real-time weather updates. This event requires a clear view of the Sun (no cloud cover). CAUTION: Never look at the Sun without a proper solar filter or you can damage your eyes.

For more information, email: astronomy-events@tucsonastronomy.org.

Visible light image of sun, with Venus transiting. The sun is a type yellow type G star approximately 4.5 billions years old with a life cycle of 10 billion years. NASA Image
Visible light image of sun, with Venus transiting. The sun is a type yellow type G star approximately 4.5 billions years old with a life cycle of 10 billion years.
NASA Image
32 inch Cassegrain Project, General Astronomy

Planets of the Month: OCTOBER 2019

by Erich Karkoschka

Planets for October 2019

planet-of-the-month-mercury Mercury is 7 degrees left and slightly above Venus for most of the month. During the last week of October, it moves below Venus. MARK YOUR CALENDAR for the transit of Mercury on November 11th.
planet-of-the-month-venus Venus is back in the evening sky visible before 6:30 pm.
planet-of-the-month-moon Shortly after New Moon, the Moon is near Venus on the 29th and near Jupiter on the 31st.
planet-of-the-month-mars Mars becomes visible again around the 19th during dawn. On the 26th it is 5 degrees below the thin lunar crescent.
planet-of-the-month-jupiter Jupiter shines above Antares in the southwest during the early evening. Its distance from Venus shrinks from 50 to 25 degrees
 planet-of-the-month-saturn  Saturn is 25 degrees to the east of Jupiter. By the end of the month only 20 degrees.
 planet-of-the-month-uranus  Uranus is in opposition on the 267th in Aries, visible with very good eyes.
 planet-of-the-month-neptune Neptune can be found with binoculars in Aquarius, 45 degrees west of Uranus.
 planet-of-the-month-meteor  The Orionids meteors are best visible during the morning of the 22nd.
32 inch Cassegrain Project, Astronomical Events, General Astronomy, Solar System

Planets of the Month: Summer 2019

by Erich Karkoschka

Planets for Summer 2019 (June – September)

planet-of-the-month-mercury Mercury is visible all June until July 3 in the evening to the WNW just after sunset. In mid-June, it is the most obvious object in the western sky. August 3 -24 it is visible during dawn in the east.
planet-of-the-month-venus Venus is a difficult dawn object until July 18. It will reappear September 18 low at dusk.
planet-of-the-month-moon The Moon is New on June 3, July 2, July 31, August 30, and September 28. First Quarter Moon is June 10, July 9, August 7, September 5. Full Moon is June 17, July 16, August 15, and September 13. There is a partial Lunar Eclipse on July 16, visible in South America and further east.
planet-of-the-month-mars Mars is above Mercury in early June. On June 18, Mercury passes close to Mars. Then, Mars slowly gets lower during dusk until it disappears in the glow of the Sun at the end of June for the rest of the summer.
planet-of-the-month-jupiter Jupiter comes in opposition to the Sun on June 10 and is a great evening object all summer. It is moving toward Antares.
 planet-of-the-month-saturn  Saturn is just 30 degrees east of Jupiter. It is in opposition July 9 and will be a great evening object most of the summer as well. The brightest parts of the Milky Way are between Jupiter and Saturn in the night sky.
 planet-of-the-month-neptune  The distant, faint planets come in opposition September 8 (Neptune) and October 28 (Uranus).
 There are two eclipses in July. A Total Solar Eclipse July 2, visible in South America, and a Partial Lunar Eclipse on July 16, visible in South America and further east.
General Astronomy, Solar System

Planets of the Month: March 2019

by Erich Karkoschka

planet-of-the-month-mars Mars is still magnitude 1, 40 degrees high at dusk, sets at 11 pm. It is moving toward Taurus with Aldebaran of similar brightness and color.  The last week of March it is 3 degrees south of the Pleiades.
Uranus is visible in binoculars below Mars.
Jupiter transits at dawn.
Venus is further east and stays low at dawn.
Saturn is 26 degrees east of Jupiter, the closest since 2001.
Mercury is visible at dusk till the 5th and at dawn starting on the 30th.
The moon is close to Venus on the morings of March 2 and 3. The moon will be back in the evening sky on the 7th as a very thin crescent low in the west.
General Astronomy, Solar System

Planets of the Month: February 2019

by Erich Karkoschka

Mercury has the best evening apparition of 2019, visible after the 12th in the west at dusk, best around the 24th.
planet-of-the-month-mars Mars is still magnitude 1, 50 degrees high at dusk, sets after 11 pm. It is moving toward Aries and Taurus with Aldebaran of similar brightness and color.
Uranus is 1 degree south of Mars on February 12. Although Mars is 100 times as bright as Uranus, both are of similar sizes, 6 arcsec versus 4 arcsec, but very different colors.
Jupiter rises at 3 am and is 30 degrees high at dawn.
Venus rises 4:30 am and is 20 degrees high at dawn.  Venus and Jupiter are only separated by 10 degrees at the beginning of the month.
Saturn rises after Venus in early February.  On the 18th, it is within 1 degree of Venus.  Saturn and Jupiter are separated by 30 degrees, the closest since 2001.
The moon will be back in the evening sky on the 6th, possibly on the 5th, very low in the WSW in bright twilight.  Binoculars may be needed to spot it depending on the atmospheric conditions.
General Astronomy, Solar System

Planets of the Month: January 2019

by Erich Karkoschka

TOTAL LUNAR ECLIPSE January 20:  8:34-11:51 pm, totality 9:41-10:44 pm. High in sky, near Castor and Pollux.  Southern limb of moon gets very close to the center of the umbra at mid eclipse (10:12 pm).
planet-of-the-month-mars Mars at magnitude 1, 60 degegrees high at dusk, sets after 11 pm.
It is moving fast through the faint stars of Pisces.
Uranus and Neptune on both sides of Mars visible in binoculars.
Venus rises 4 am at brillant magnitude -4.5, high during dawn,
naked eye visibility after sunrise.
Jupiter at magnitude -2 rises first at 5 am. Jupiter and Venus approach each other.
Closest on 21st, 2.5 degrees separation, spectacular around 6 am!
Comet Wirtanen, magnitude 5 and dimming, moves fast from Lynx to
Ursa Major, circumpolar.
The moon will be close to Mars on the 12th and close to Venus on
the 31st.
Latest sunrise is January 8.
32 inch Cassegrain Project, General Astronomy, Star Parties

Comet 46P Wirtanen from CAC

We have a naked eye (from a dark site) comet visible (arrow). It is Comet 46P Wirtanen. Ed Foley, one of our TAAA members, took this picture from our Chiricahua Astronomy Complex dark-sky site during last weekend’s events (Saturday December 8, 2018). You can see one of our observatories as well. Those present observed it through several telescopes. It was also observed at last Saturday’s Ironwood Picnic Star Party and will be observed at this coming weekend (December 15) Agua Caliente Park star party.

46 P Wirtanen over Wally Rogers Observatory 2 (compressed)

General Astronomy, Solar System

Planets of the Month: December 2018

by Erich Karkoschka

planet-of-the-month-saturn Saturn is still visible at dusk very low in the southwest until Dec 15.
planet-of-the-month-mars Mars at magnitude 0 transits at 6pm and sets at midnight. It is moving fast through Aquarius.
planet-of-the-month-neptune Neptune is easy to find on Dec 7 when it is only 15 arc-minutes from Mars.
planet-of-the-month-uranus Uranus transits at 9pm 68 degrees high in Pisces.
planet-of-the-month-venus Venus is magnitude -4.9, the brightest possible, high during dawn.
planet-of-the-month-mercury Mercury is visible well below Venus from Dec 4 to Jan 4.
planet-of-the-month-jupiter Jupiter joins Mercury starting Dec 9 first below Mercury. On Dec 21, the pair is only 1 degree apart.  Afterwards, Jupiter will be higher than Mercury by 1 degree per day.
planet-of-the-month-moon The moon will be first visible on Dec 8 as a very thin crescent next to Saturn.  On Dec 14 it shines below Mars.
planet-of-the-month-meteor The Geminids meteors will be very active on Dec 13 an 14.
winter-solstice Winter solstice occurs on Dec 21. The length of the day stays near 10 hours all month, but sunrise and sunset both get delayed by about a quarter of an hour during December.