All posts by Jim Knoll

Planets of the Month – April 2024

by Erich Karkoschka

The New Moon on the 8th brings a partial solar eclipse in Tucson during late morning It is total on a path from Mazatlan in Mexico, through Texas, to the Great Lakes. The following day, the thin crescent can be seen just before 8 pm.

Venus rises during the dawn and may be visible naked eye, at least during the first half of the month.

Mars is rising earlier, but it still is not very high when dawn starts.

Jupiter is visible in the west after dusk. By the end of the month it sets at 8 pm, just as it gets dark.

Saturn starts the month just to the lower left of Mars. On the 10th, both planets are only half a degree apart from each other. Both have the same brightness, but not the same color. By the end of the month, Saturn is much higher than Mars, and its rings are quite narrow.

Uranus gets passed by Jupiter on the 20th when they will be only half a degree apart from each other.

Comet 12P/Pons-Brooks is in the vicinity of Jupiter and may be fifth magnitude. It is heading south and is getting really low after mid-month.

32 inch Cassegrain Project

Planets of the Month – February – March 2024

By Erich Karkoschka

Saturn is only visible until February 11 during dusk.

Mercury starts its best evening visibility of the year on March 10.

Jupiter transits high at sunset at the beginning of February. However, by the end of March it is already down to 20 degrees high in the west when it becomes visible right after sunset.

Uranus is high in the evening sky and sets around midnight.

Venus and Mars are visible during dawn. First, Mars is difficult to see 10 degrees to the lower left of Venus. On February 22, they are only .6 degrees apart from each other with Venus 100 times brighter than Mars. Then Mars will be to the upper right of Venus with their distance increasing to 18 degrees by the end of March.

The Moon has two conjunctions with Jupiter on February 14 and March 13. The close conjunction with Mercury or February 11 is also interesting to watch since the moon will be a very thin crescent.

There is a penumbral lunar eclipse at midnight of March 24. Since it is almost partial, the darkening will be quite obvious.

32 inch Cassegrain Project

Planets of the Month – January 2024

By Erich Karkoschka

Saturn is well visible during the early evening. It sets around 8 pm. Soon it will be too close to the Sun. When it reappears in the Spring, Saturn’s rings will only be half as open as now.

Jupiter transits during dusk. It is very high and good for telescopic observations. On the 20th, Ganymede is transiting the disk after 10 pm, visible as a dark spot.

Uranus is high in the evening sky east of Jupiter.

Neptune is west of Jupiter.

Brilliant Venus is best observed between 5 and 6 am, just before down starts.

Mercury joins Venus, visible until the end of the month. It is to the lower left of Venus around 6-7 am. There is no other star at similar brightness in this area of the sky. If you see one, it is Mercury.

Mars is within half a degree of Mercury on the 27th. Since it is a magnitude fainter then Mercury, it may require very clear air to make it out naked eye. Binoculars will easily show this close pair.

32 inch Cassegrain Project

Planets of the Month – December 2023

By Erich Karkoschka

Mercury has a modest evening visibility until December 14th. Look to the southwest around 6 pm with no star nearby to confuse it with.

Saturn transits before dark and is well visible until late evening.

Jupiter shifts its transits from 10 pm to 8 pm during the month. Its elevation is then 70 degrees and its 48 arc-second diameter is perfect for telescope viewing.

Venus comes up around 4 am and is almost 40 degrees high in the southeast by the time the sun rises.

Uranus is east of Jupiter and Neptune is east of Saturn. Both are placed well for evening observation with binoculars.

Vesta, minor planet number 4, comes into opposition on December 21st (Winter Solstice). It therefore is very close to the point where the sun is at the summer solstice, between Taurus and Gemini. Its magnitude of 6.4 is at the limit of naked eye visibility.

The Moon visits Venus on December 19th, when Venus is easily visible after sunrise and perhaps even at noon as the moon is a guide to the location of Venus. The Moon is close to Saturn on the 17th.

December 13th is one of the best times of the year to watch meteors as the Gemini’s peak that evening.

Star Parties

December 18, 2023 Chiricahua Astronomy Complex Telescope Observing

If you have family in town for the Holidays, whether you are a TAAA member or not, and want to participate in a telescope observing session at our Chiricahua Astronomy Complex (CAC), we are offering a two-hour observing session for a nominal fee per person. This is a perfect way to show family & visitors our dark skies and great astronomy conditions. The fee for the session is $50/adult and $25/youth under age 16.

We will be observing several planets to include Saturn and Jupiter, Galaxies millions of light years away, multiple star systems with stars orbiting around each other, star clusters, nebulae, and much more.

Observing will be Monday December 18, 2023 from 6 – 8 pm. To reserve, please make a reservation using the form at: https://tucsonastronomy.org/tsa-at-our-dark-site/ and input the December 18th date in the “Requested Date” field. We will send you an invoice to pay the required fee (fully refundable if you cancel at least 48 hours in advance or if we have weather issues the evening of the event).

Chiricahua Astronomy Complex Address: 9315 E Perseus Way, Pearce, AZ (about 1.5 to 2 hours SE of Tucson near the Chiricahua Mountains). More information on CAC is available at: https://tucsonastronomy.org/taaa-member-resources/observing-sites/chiricahua-astronomy-complex/

For any questions, email the CAC Director at: cac-director[at]tucsonastronomy.org.

32 inch Cassegrain Project

Planets of the Month — November 2023

By Erich Karkoschka

Saturn transits just after dark. Its rings are tilted less than during the last 10 years.

Jupiter is at opposition on the 3rd with an almost maximum magnitude of -2.8. It transits 71 degrees high. On the 24th, Ganymede transits on Jupiter’s disk early in the evening, followed by its shadow, lasting until 9 pm.

Uranus is at opposition on the 13th. It lies 10 degrees east of Jupiter at magnitude 5.6.

Neptune is between Jupiter and Saturn.

So, there are all four giant planets in the evening sky.

Venus is just past greatest elongation and very conspicuous at the beginning of dawn.

The Moon is close to Jupiter on the 24th and 25th.

What We're About

2023 Annular Eclipse Photos

Several TAAA members traveled to Roswell New Mexico to view the 2023 Annular Eclipse. Roswell was along the centerline. While in Roswell, we did an outreach event for those in the area.

Pictures of the Eclipse from Bernie Stinger using a Lunt 60mm Ha Solar Scope.

Images of the Eclipse from Tom Sarko using a DSLR Camera with Solar Filter.

Several TAAA Members also supported the Flandrau Science Center on the University of Arizona in Tucson for a large outreach event showing the partial phase of the Annular Eclipse.

32 inch Cassegrain Project

Planets of the Month: September & October 2023

By Erich Karkoschka

Saturn is 45 degrees high during the late evening. Rings are almost half open, the last time for several years.

Jupiter rises at 10 pm during early September, but close to sunset by late October. Its magnitude reaches -2.9, which is as high as it ever gets. Jupiter transits 73 degrees high during the morning hours.

Uranus is 10 degrees east of Jupiter at magnitude 5.7, getting closer to the Pleiades.

Neptune is between Jupiter and Saturn at magnitude 7.8. It reaches opposition on September 19.

Venus rises at 4 am, but later already at 3 am. It is high up by sunrise and is a large crescent in September, reaching half phase in late October. It is brightest in mid-September, and at -4.8, it is really bright. One could find it during daytime, for example around 9:30 am 65 degrees high in the south, or close to the moon September 11-12 and October 10.

Mercury is a morning object from September 15 to October 6, rising at 5 am below Regulus, which is below Venus.

The moon passes Jupiter on September 4, October 1 and 28. It is close to Pollux on the morning of October 7.

Arizona gets its second and last annular solar eclipse on October 14 with a maximum around 9:35 am. Tucson gets a good partial eclipse, while Four Corners (and parts of New Mexico) get the annular phase. A great event to watch, especially with a filtered telescope. Always use an approved SOLAR FILTER for observing Partial and Annular Eclipses.

32 inch Cassegrain Project

Planets of the Month: August 2023

By Erich Karkoschka

Mercury is visible around 8 pm in the west until August 16th.

Mars is about 5 degrees to the upper left during this time, just a little dimmer, but still visible since it is higher up. By the end of the month it becomes hard to find. It will reappear in March 2024. During the first week of August, both planets are best visible. Around the 13th, they are closest together.

Saturn in Aquarius is visible all night since it is at opposition on the 27th. Its rings are narrow, 43″ x 6″ in extent.

Jupiter in Aries rises now before midnight, outshining all stars and other planets.

Venus rises up to become visible starting on the 18th during dawn. It is obvious by the 31st, when a 10 percent illuminated crescent shows up in binoculars. Venus is near the head of Hydra, where other planets do not go.

The moon occults Antares on the 24th between 7:03 and 7:58 pm AZ Time in Tucson. The disappearance is a few minutes after sunset, when it is easily visible in binoculars and impressive in a telescope near the half moon. It occurs at the dark side of the moon which is not visible during bright twilight. The reappearance is at the bright limb, when the sky is dark.

The Perseids are active until mid-month, visible without moonlight. The maximum is the night of the 12th, morning of the 13th. Best viewed under dark skies at the peak after midnight on the morning of the 13th. Look toward the east. The meteors will appear to emanate from the constellation Perseus. The parent comet is Swift-Tuttle (16 miles/26 kilometers across).

32 inch Cassegrain Project

Planets of the Month: July

By Erich Karkoschka

This month marks the end of the evening visibility of Venus. It perhaps is visible until August 3. This is the greatest time for telescopic observations since it shows a large crescent. By the 31at, it is only illuminated by 6%.

Mars is 3 degrees east of Venus but the separation increases since Venus is stationary on the 21st while Mars keeps on going. Mars passes 1 degree north of Regulus on the 9th and 10th.

Mercury appears in the evening sky on the 12th, passing Regulus on the 28th.

The moon passes those three planets including Regulus on the 18th to 20th. On the 18th it is still very difficult to find. On the 19th it is right in the middle of them. On the 20th it is close to Mars.

Saturn rises during the late evening. Its rings are almost edge-on.

Neptune follows an hour later.

Jupiter rises after midnight and is very high by dawn.

Uranus is 10 degrees east of Jupiter in the morning sky.