This is the Saint Louis Science Center’s NIGHT SKY UPDATE for the week of Friday, October 16, 2020.
Information updated weekly or as needed.
Times given as local St. Louis time (CDT). For definitions of terminology used in the night sky update, click the highlighted text.
Public Telescope Viewings
Star parties at the Saint Louis Science Center have temporarily been canceled due to recommendations from the CDC regarding COVID-19. All public telescope events are canceled until further notice. As conditions change, we will reevaluate and update this article once public observing events resume.
Observing Highlight of the Week
Orionid Radiant on October 21, 2020 at 12:00 am
Credit: Stellarium, EG
The highlight for this week is the Orionid Meteor Shower. Every year from October through the first week of November, Earth passes through debris from Comet 1P/ Halley. This famous periodic comet was last seen in 1986 and is expected to return in 2061. Each time it orbits the Sun, Comet Halley leaves debris that eventually becomes the source of the Orionids. This meteor shower is moderate at best producing about 20 meteors per hour if viewed from a dark location. Its peak will come on October 20/21 with the best views in the hours before sunrise on October 21.
This meteor shower is called the Orionids because the radiant for the shower occurs in the constellation Orion. The radiant of a meteor shower is where its meteors appear to emanate from moving in all directions. It is not the only place you should look but it is important to be aware of its location. The radiant for the Orionids is found near the northern edge of the constellation. It will rise around 10:30 pm clearing trees in the east by 11:30 p.m. Your best chance to see meteors will come after midnight once Orion is higher in the sky. If viewing from a light polluted location, meteors are still possible to see but they will be much less then posted peak rates.
The Sun and Moon
The Moon as seen from the International Space Station, on July 31, 2011.
Sunrise is at 7:12 a.m. on Friday, October 16 and sunset is at 6:21 p.m. providing us with a little over 11 hours of daylight. Even after sunset, the light from the Sun will dimly illuminate our sky for about 1 hour and 30 minutes. This period is called twilight, which ends around 7:49 p.m. this week. For those with a sundial, local noon occurs around 12:46 p.m. this week.
|2020-10-16||7:12 a.m.||6:21 p.m.|
|2020-10-17||7:13 a.m.||6:19 p.m.|
|2020-10-18||7:14 a.m.||6:18 p.m.|
|2020-10-19||7:15 a.m.||6:16 p.m.|
|2020-10-20||7:16 a.m.||6:15 p.m.|
|2020-10-21||7:17 a.m.||6:14 p.m.|
|2020-10-22||7:18 a.m.||6:12 p.m.|
|2020-10-23||7:19 a.m.||6:11 p.m.|
|2020-10-24||7:20 a.m.||6:10 p.m.|
Moonrise for Friday, October 16 occurs at 6:47 a.m. and moonset will occur at 6:40 p.m. On Friday, October 16 the Moon will exhibit a new moon phase and will not be visible. The rest of the week the Moon will exhibit a waxing crescent phase and will be seen in the west after sunset.
International Space Station (ISS) Observing
Visible passes of ISS from St. Louis for the week of October 16 occur during morning hours. The best passes this week occur on October 22 and 23. Use the table below for information about these and other visible passes this week.
Catch ISS from St. Louis starting Friday, October 16
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°.
For information about ISS flyovers and other visible satellites, visit www.heavens-above.com
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 Southeast, at 8:00 pm, October 16, 2020
Credit: Stellarium, EG
Looking East, 5:00 am, October 17, 2020
Credit: Stellarium, EG
This week, four naked eye planets are visible. Jupiter and Saturn rise before sunset. Look for them in the south once it is dark. Mars rises before sunset and will be best seen at midnight. Venus can be found in the eastern sky before sunrise.
For those tracking Jupiter and Saturn as they approach their great conjunction later this year, the two gas giants currently appear about 6.25° apart in the sky. From now until December 21, Jupiter will appear closer to Saturn each night.
Venus is well into another morning apparition. After months of seeing Venus in the west after sunset Venus is now visible in the east before sunrise. Venus rises at 4:09 a.m. and will be easily seen by 5:00 a.m. Venus remains a morning object until March 26, 2021 when it reaches superior conjunction. Since Venus has passed greatest western elongation, it will start to exhibit a gibbous phase.
Mars has passed opposition and now rises before the Sun. Surface features will still be visible through telescopes for some time, but Mars will start to fade as Earth is now moving away from Mars. Observing season for this apparition ends around March 10, 2021 and superior conjunction occurs on October 7, 2021. Currently Mars appears as a -2.6 magnitude object that will be visible in the east about 30 minutes after sunset.
Look for Jupiter in the south about 30 minutes after sunset. Jupiter will set at 11:21 p.m. Those with a telescope can enjoy views of Jupiter’s cloud features and the Great Red Spot when it is pointed towards Earth.
Look for the ringed planet in the south about 30 minutes after sunset. Saturn sets at 11:53 p.m. For those with a telescope keep track of the orientation of Saturn’s rings. Since Saturn is tilted on its rotational axis, we cross the plane of Saturn’s ring every 13 to 15 years. We are headed towards another ring plane crossing on March 23, 2025. Over the next five years you will notice Saturn’s rings will gradually incline towards an edge on appearance.
Uranus is not a planet we normally include in this section. Even at its dimmest, the giant planet does hover within naked eye visibility. That said, it is so close to the visible limit of the human eye it just is not reality for most of us to hope to see Uranus without the aid of binoculars or a telescope. Uranus will rise around 6:58 p.m.
Like other planets, when at opposition, Uranus will appear brighter than it normally does. As we approach opposition with Uranus it will shift from a visual magnitude of 5.9 to 5.7. That extra bump in magnitude makes all the difference as it is now easy to see in binoculars. The current magnitude for Uranus is 5.7. Uranus will reach opposition on October 31, so grab those binoculars and try to spot the 3rd largest planet in our solar system. You can find a finder chart for Uranus here
2020 Great Conjunction
This year the planets Jupiter and Saturn will reach conjunction. A conjunction is when two or more celestial bodies share the same right ascension. For Jupiter and Saturn this astronomical event occurs every 20 years. The conjunction occurs on December 21, 2020. You will find the two planets close together in the southwest just after sunset on this date.
Visit the James S. McDonnell Planetarium for more information on what’s up!
Night Sky Update: October 16-October 24, 2020