This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Saturday, February 15, 2025.
Information updated weekly or as needed.
Times given as local St. Louis time this week will be in Central Standard Time (CST). 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 -6 hours when CST. Times posted in the Night Sky Update are in the 24-hour format.
Join us for our next star party, Friday, March 7, 2025, held in association with the St. Louis Astronomical Society.
Observing Highlight of the Week
T CrB Nova Update 2/15/2025
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. It could happen this year or it could happen next year. We will have to wait and see. If you are still interested in this event, the part of the sky the nova will appear in is rising earlier each night. By 1:30 am, the constellation Corona Borealis will be over 10° above the eastern horizon. This should make it visible for most if you have a decent view of the east. Spaceweather.com is still posting magnitude estimates from the AAVSO. This is the resource I recommend following to keep up with any changes in the star’s brightness. Current magnitude of the system is 10.0.
The Sun and Moon
The Moon as seen from the International Space Station, on July 31, 2011.
Credit: NASA
Sun
Sunrise is at 6:51 on Saturday, February 15 and sunset is at 17:39 providing roughly 11 hours of daylight. Even after sunset, light from the Sun will dimly illuminate our sky for about 1 hour and 30 minutes. This period is called twilight, which ends around 19:08 this week. For those with a sundial, local noon occurs around 12:15 on February 15, 2025.
Moon
Moonrise for Saturday, February 15, is at 20:55 and moonset occurs at 8:39 the following morning. The Moon starts the week off with a waning gibbous phase exhibiting 91% disk illumination. By the end of the week the Moon will exhibit a waning crescent phase with 23% disk illumination. Last quarter moon occurs on February 20, 2025, at 11:33. Daytime views of the moon will be best in the morning around this date.
International Space Station (ISS) Observing
Passes of ISS visible from St. Louis for the week of February 15, occur in early morning hours. The table below lists the best of these passes that will be seen from St. Louis. If you do not live in the area, you can use https://heavens-above.com/ to set your viewing location and get times for where you are.
Magnitude (Mag): The Measure of brightness for a celestial object. The lower the value is, the brighter the object will be.
Altitude (Alt): The angle of a celestial object measured upwards from the observer’s horizon.
Azimuth (Az): The direction of a celestial object, measured clockwise from an observer’s location with north being 0°, east being 90°, south being 180° and west being 270°.
Detailed information regarding all unmanned exploration of our universe, missions past, present, and planned, can be found at Jet Propulsion Laboratories
The Visible Planets
Looking south at 18:20 on February 15, 2025. Credit: Stellarium, EG
This week, four naked eye planets are visible. All four are visible in the evening sky not long after sunset. As we start to lose Saturn at the end of the month, Mercury will join the evening sky for a brief apparition.
Venus
Venus will be visible in the southwest after sunset. You can start looking for Venus about 15 minutes after the Sun sets. Venus will set by 20:56. Venus is now headed towards inferior conjunction which occurs on March 22, 2025. Over the next couple of months, Venus will continue to appear closer to the Sun until we lose Venus to the Sun’s glare.
Mars
Mars is now past opposition. Look for it rising in the east after sunset. The current apparition of Mars will continue throughout the rest of 2025. Watch for the Red Planet as it shifts westward through the year.
Jupiter
Now past opposition, Jupiter rises before the Sun sets. Look for Jupiter overhead as the sky begins to darken. Jupiter sets around 2:08.
Saturn
Saturn will be visible in the southwest shortly after sunset. Saturn now sets around 19:14. Each week Saturn will set about 30 minutes earlier than it did the week before. Saturn reaches superior conjunction on March 12, 2025. Most will lose sight of Saturn by the end of February.
Saturn and Mercury will reach conjunction on February 25, 2025. If you have a clear view of the west on this date, you may be able to find Saturn near brighter Mercury about 7° above the western horizon around 18:10. You will need binoculars to have a chance of spotting the planets as this will be only 20 minutes after sunset. Before you look make sure the Sun has set before you look. Sunset on February 25, 2025, is at 17:50.
Our next Star Party will be held on Friday, March 7, 2025, from 5:30 pm until 8:30 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. Regardless of the weather on March 7, join us indoors in our planetarium theater for our “Monthly Sky Lecture”. Showtime is at 7 p.m. This free, indoor star program will introduce you to the current night sky. Doors open 15 minutes before show time. Shows begins at 7 pm Sorry, no late admissions due to safety issues in the darkened theater.
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 on the 3rd Sunday of 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: February 15-23, 2025
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