This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Tuesday, August 11, 2026
Information updated weekly or as needed.
Times given as local St. Louis time this week will be in Central Daylight Time (CDT). For definitions of terminology used in the night sky update, click the highlighted text. If relying on times posted in Universal Time (UT), St. Louis is -5 hours when CDT. Times posted in the Night Sky Update are in the 24-hour format.
Join us for our next star party, Friday, September 4, 2026, held in association with the St. Louis Astronomical Society. For details, see the information at the bottom of this page or visit https://www.slsc.org/explore/mcdonnell-planetarium/public-telescope-viewings/
Observing Highlight
The Perseid can be seen rising in the northeast after 10pm. The best views come after midnight when the radiant is found higher in the sky. Image created using Stellarium.
This week several events of interest occur involving the Moon, planets and the year’s best meteor shower. The Moon will pass through the remainder of its waning crescent phase on its way to new moon on August 12, 2026. Venus reaches both dichotomy and greatest elongation this week and lastly, the Perseid meteor shower peaks on August 12/13, 2026.
For a number of months now, Venus has been easy to find in the west after sunset. While this apparition persists into October, Venus will become harder to find after mid-September due to its altitude after sunset. This week, Venus reaches dichotomy and greatest elongation. Dichotomy occurs when we see half of Venus in daylight and the other half in nighttime. Greatest elongation is when Venus’s angular separation from the Sun is its greatest. These events usually happen within a few days from each other, and they indicate when Venus starts moving towards a conjunction.
Dichotomy occurs on August 12, 2026, after which Venus enters its crescent phase decreasing disk illumination each day. A few days later on August 15, 2026, Venus reaches greatest eastern elongation. Once this occurs, Venus will slowly shift back towards the Sun on its way to inferior conjunction on October 23, 2026.
The morning sky is becoming increasingly busy with planets as Mars and Saturn are now easy to find in the east and south respectively. Jupiter is still a little too low for many to find but it will soon join Mars and Saturn is the morning sky. You can find Saturn rising this week around 22:30 becoming easily seen about an hour later. Mars rises around 02:20 becoming easily visible about an hour later.
Both Mercury and Jupiter will rise before the Sun, but they will be found below the 10° threshold. If you have a clear view to the east, you have a slim chance of seeing both planets around 05:45. You will have to use binoculars to find both planets due to the bright glow of twilight.
If you are one of the lucky few who have clear views to the eastern horizon, keep August 15, 2026, in mind. Mercury and Jupiter will reach conjunction that morning. While the closest approach of the pair occurs before they rise in St. Louis, there is a slim chance to seem them around 05:50. Unfortunately, the Sun will rise about 20 minutes later making the pair very difficult to find. At this time, they will appear 6.5° above the eastern horizon at azimuth 71.9°. If you plan to attempt this please exercise caution and ensure the Sun has not risen.
Keep Jupiter in mind as next month on September 8, 2026, Jupiter will be occulted by the Moon. The occultation occurs from 12:03 to 15:25 CDT, making it a daytime event. You will need to use a telescope to view this event. As always use caution anytime you are using telescopes in the daytime.
Lastly, The Perseid meteor shower peaks the week on August 12/13, 2026. Most years, Zenith Hourly Rates (ZHR) during the peak are expected to be 100 meteors per hour if viewing from a dark location. The American Meteor Society’s article on the Perseids posted by Robert Lunsford, suggest that the peak is likely to be lower this year with peak ZHR reaching only 40 meteors per hour. The article also states that meteor shower expert Mikhail Maslov believes the Perseids will return to enhanced activity by 2027.
Many are excited for this year’s Perseids because the peak coincides with new moon. With little interference from moonlight, it will be easier to see the fainter meteors. It also turns out that a solar eclipse happens on August 12, 2026. The last time the peak of the Perseids lined up with a solar eclipse happened in 1942. Unfortunately, the solar eclipse this year is not visible in St. Louis. However, the next time a solar eclipse lines up with the peak of the Perseid is on August 12, 2045. This eclipse is visible in St. Louis but to see totality, you will need to drive down to Oklahoma or Arkansas for the closest location.
To view meteor showers, you want to keep a few things in mind. Most important, you need to get to as dark a place as you can. Viewing from light polluted locations will dramatically diminish what you see. You also need to be aware of where a meteor shower’s radiant is located. This is the point in the sky that meteors appear to emanate from. The constellation Perseus is where the Perseid radiant is found. It is not necessary to look at this spot at all times but understanding its location informs where you will see meteors.
The Perseid radiant will clear trees in the northeast around 10pm. At this time, views of meteors will be limited to those moving away from the northeastern horizon. As the radiant appears higher overhead, you will start seeing meteors moving away from the radiant in all directions. This makes our best chance to see meteors between 02:00 and 04:34 when astronomical twilight begins.
Watch the weather as thunderstorms may be in our area on both August 12 and 13. Hopefully, skies will clear at night making views possible. If the weather keeps us from seeing meteors this year, the Perseids return each year being active from July 17 to August 29.
T CrB Nova Update 8/11/2026
If you are still interested in seeing the recurrent nova T Coronae Borealis, there is still hope. The nova has not yet occurred meaning we are in a waiting game. If you are still interested, the part of the sky the nova will appear in is found high in the west by the time it is dark. The star system T Coronae Borealis is found in the constellation Corona Borealis which looks like a small U-shape of stars next to the constellation Boötes. By 10 pm the location of T CrB will be overhead. If you cannot observe the sky directly, you can track the behavior of T CrB by checking current magnitude estimates posted at AAVSO here or by visiting spaceweather.com. Current magnitude estimates of the system show it at 10th magnitude.
The Sun and Moon
Sun
Sunrise on Tuesday, August 11 is at 6:11 and sunset is at 20:00 providing around 13.5 hours of daylight. Even after sunset, light from the Sun will dimly illuminate our sky for about 1 hour and 40 minutes. This period is called twilight, which ends around 21:41 this week. For those with a sundial, local noon occurs around 13:06 on Aug 11, 2026.
| Day | Sunrise (CDT) | Sunset (CDT) |
| 11-Aug | 6:11 | 20:00 |
| 12-Aug | 6:12 | 19:59 |
| 13-Aug | 6:13 | 19:57 |
| 14-Aug | 6:14 | 19:56 |
| 15-Aug | 6:15 | 19:55 |
| 16-Aug | 6:16 | 19:53 |
| 17-Aug | 6:17 | 19:52 |
| 18-Aug | 6:18 | 19:51 |
| 19-Aug | 6:18 | 19:49 |
| 20-Aug | 6:19 | 19:48 |
| 21-Aug | 6:20 | 19:47 |
Moon
Moonrise for Tuesday, August 11, was at 04:39 and moonset occurs at 19:35. On August 11, 2026, the Moon will exhibit a waning crescent phase with 1% disk illumination. By August 21, 2026, the Moon will exhibit a waxing gibbous phase with 66% disk illumination. New moon occurs on August 12, 2026, at 18:57. First quarter moon occurs on August 19, 2026, at 21:46.
International Space Station (ISS) Observing
Visible passes of ISS from St. Louis for the week of August 11 occur during morning hours. The best of these occur on August 16, 18 and 19. You can find information about these and other satellite passes at https://heavens-above.com. If you are not viewing from the St. Louis area, make sure to change your viewing location for your local times.
Visible Planets
View looking west on August 11, 2026, at 20:15. Image created using Stellarium
View looking east on August 12, 2026, at 04:00. Image created using Stellarium
Three naked eye planets will be visible this week. Venus is found in the west after sunset. Saturn and Mars are visible in the south and east before sunrise.
Venus
Venus is visible in the west after sunset. Venus will reach maximum eastern elongation on August 15, 2026. Its current evening apparition will continue until October as it approach inferior conjunction on October 23, 2026. Venus sets by 21:46.
Mars
Mars rises around 02:18 this week clearing the 10° mark by 03:20. By 04:00, Mars can be found about 18° above the eastern horizon. This apparition of Mars is not the best as it is an aphelic apparition. ALPO’s guide for the Mars 2026-2027 aphelic apparition shows October 14, 2026, as the beginning of the apparition for those using telescopes between 4 and 8 inches. This is the time frame in which most observers can start seeing the surface of Mars through their telescope. Mars reaches opposition on February 19, 2027.
Saturn
Saturn can be found rising in the east around 22:25 clearing the 10° mark by 23:20. Saturn will continue to rise earlier each week until it reaches opposition on October 4, 2026.
Our next Star Party will be held on Friday, September 4, 2026 from 6:30 pm to 9:30 pm.
On the first Friday of each month, the St. Louis Astronomical Society and the Saint Louis Science Center will set up a number of telescopes outdoors and be on hand to answer your questions. Telescope viewing begins once it is dark.
The St. Louis Astronomical Society helps host the monthly Star Parties at the Saint Louis Science Center. In addition to our nighttime viewings, they also help facilitate our daytime event called Solar Sundays. These daytime viewing sessions occur every Sunday through Labor Day. After Labor Day they occur on the 3rd Sunday each month. Visit SLAS’s website linked above to learn about other telescope events SLAS hosts around the St. Louis area.
James S. McDonnell Planetarium
Night Sky Update for August 11, 2026
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