Here are this week’s best astronomical events that you can view right from your backyard. Below is a picture of Orion, featured on APOD this week. And here are even more pictures of Orion to love, if you’re interested. I’d love to know what you discover in the night sky! Happy exploring!
Learn from yesterday, live for today, hope for tomorrow. The important thing is not to stop questioning. –Albert Einstein
You can use the star chart provided here. And for any terms or units you may be unfamiliar with, I’ve provided a glossary at the end of the guide for your convenience. All events were calculated based on Boulder, CO (latitude 40⁰ N), but should provide good approximations for most cities near the same latitude. If you would like, you can change your location on the linked sites for each event. Let me know if you have any questions. I’d love to know what you see this week!
Thursday 11/26
05:09 MST ISS Passing
The ISS will make a visible pass (magnitude -1.9) starting at 28⁰ elevation in the South and moving SSE. More information here.
18:18 MST Iridium Flare (Iridium 32)
The Iridium 32 satellite will cause an iridium flare of magnitude -1.0 that will be seen as a bright flash across the sky. The flare will begin at an elevation of 32⁰ in the SSE. More information here.
Friday 11/27
18:02 MST Resurs 01 Rocket Passing
The Resurs 01 Rocket will make a visible pass (magnitude 1.8) starting at 10⁰ elevation in the SE and moving ENE, reaching a highest elevation of 46⁰. More information here.
Saturday 11/28
06:48 MST Iridium Flare (Iridium 91)
The Iridium 91 satellite will cause an iridium flare of magnitude -8.4 that will be seen as a bright flash across the sky. The flare will begin at an elevation of 70⁰ in the NNW. More information here.
Sunday 11/29
03:17 MST Venus at Perihelion
Venus will reach the closest point in its orbit to the Sun, 0.72 AU from the Sun. Because Venus follows an almost circular orbit, its distance only varies by 1.5% between aphelion and perihelion. From Boulder, Venus will be visible in the dawn sky starting at 03:17 MST and attain an elevation of 33⁰ above the SE horizon. It will fade as dawn breaks around 06:40 MST. More information here.
16:42 MST Iridium Flare (Iridium 46)
The Iridium 46 satellite will cause an iridium flare of magnitude -5.7 that will be seen as a bright flash across the sky. The flare will begin at an elevation of 20⁰ in the SW. More information here.
17:34 MST Iridium Flare (Iridium 22)
The Iridium 22 satellite will cause an iridium flare of magnitude -1.5 that will be seen as a bright flash across the sky. The flare will begin at an elevation of 12⁰ in the West. More information here.
Monday 11/30
17:19 MST Iridium Flare (Iridium 76)
The Iridium 76 satellite will cause an iridium flare of magnitude -5.3 that will be seen as a bright flash across the sky. The flare will begin at an elevation of 15⁰ in the West. More information here.
11:18 MST Saturn at Solar Conjunctions
Saturn and the Sun will be very close (as viewed from Earth), passing within 1⁰38’ of each other. This will make Saturn unobservable for several weeks while it is lost in the Sun’s glare. During this time, Saturn will also reach apogee, the point in its orbit farthest from Earth. It will lie at a distance of 10.99 AU from the Earth, making it appear very small in the sky (~15.1 arcsec in diameter). More information here.
18:03 MST Iridium Flare (Iridium 57)
The Iridium 57 satellite will cause an iridium flare of magnitude -3.8 that will be seen as a bright flash across the sky. The flare will begin at an elevation of 32⁰ in the South. More information here.
Tuesday 12/1
06:30 MST Iridium Flare (Iridium 30)
The Iridium 30 satellite will cause an iridium flare of magnitude -4.8 that will be seen as a bright flash across the sky. The flare will begin at an elevation of 65⁰ in the NNW. More information here.
17:04 MST Iridium Flare (Iridium 23)
The Iridium 23 satellite will cause an iridium flare of magnitude -5.6 that will be seen as a bright flash across the sky. The flare will begin at an elevation of 18⁰ in the West. More information here.
Wednesday 12/2
18:18 MST Resurs 01 Rocket Passing
The Resurs 01 Rocket will make a visible pass (magnitude 1.4) starting at 10⁰ elevation in the SSE and moving ENE, reaching a highest elevation of 77⁰. More information here.
Glossary
Apogee: The point in the orbit farthest away from the Earth.
Apehelion: The point in the orbit farthest away from the Sun.
Arcminute: An angular measurement, defined as 1/60 of one degree. Denoted by ‘. (approx. 1 inch at a distance of 100 yards, the Moon is approx 31’)
Arcsecond: An angular measurement, defined as 1/60 of an arcminute. Denoted by “. (approx. dime at a distance of 1 mile )
A great resource for understanding and approximating angular measurements in the night sky, here. The Moon is approx 1/2⁰. Your outstretched hand is approx 20⁰, with each finger approx 1⁰. Your closed outstretched palm is approx 10⁰.
AU: Astronomical Unit, Defined as the distance between the Sun and Earth.
Conjunction: An alignment of two celestial bodies such that they present the least angular separation as viewed from Earth.
Elongation: The angle between the Sun and a planet, with Earth as the reference point. The greatest elongation of a planet occurs when this separation angle is at its largest. More information here.
Iridium Flare: Iridium fares occur when sunlight is reflected off the antenna (of one of the 66 active telecommunication sats in LEO, known as the Iridium constellation) directly down at Earth. This reflection causes an illuminated spot on the surface of the Earth. To an observer on the ground, the event appears to be a bright flash, or flare in the sky, which lasts for a few seconds.
ISS: International Space Station. More information here.
Magnitude: A logarithmic measure of the brightness of an object. Brighter objects have a lower (more negative) magnitude. More information here.
Opposition: When a celestial body is opposite the Sun in the sky.
Perigee: The point in the orbit closet to the Earth.
Perihelion: The point in the orbit closest to the Sun.
Radiant: The point in the sky where meteors of a meteor shower appear to originate.
Time Conversions from MST
Eastern Daylight Time, EST = MST + 2:00
Central Daylight Time, CST = MST + 1:00
Mountain Daylight Time, MST
Pacific Daylight Time, PST = MST – 1:00
Alaska Daylight Time, AKST = MST – 2:00
The standard for astronomical times is UTC if you happen to come across it, where MST = UTC – 6:00.
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