The constellation Gemini is nearly overhead in the predawn sky – look for the two bright stars, Pollux and Castor near the constellation Orion.
The constellation Gemini, with Orion nearby, directly overhead before dawn. Note: using H. A. Rey constellation lore. Credit: Stellarium / Bob Trembley.The constellation Leo with the bright star Regulus rises earlier each day in the eastern predawn sky.
The bright star Regulus in the constellation Leo in the eastern predawn sky. Note: using H. A. Rey constellation lore. Credit: Stellarium / Bob Trembley.The Moon joins Mars and Saturn in the southern sky after sunset this week.
The Moon joins Mars and Saturn in the southern sky after sunset on Oct. 16, 2018. Credit: Stellarium / Bob Trembley.Jupiter is the “evening star,” appearing low in the southwestern sky at dusk, and setting shortly after dark. If you have a clear horizon, you might be able to catch a glimpse of Mercury a few minutes after 5:00 PM.
Jupiter and Mercury (maybe a bit too low to see) in the southwestern sky at dusk on Oct. 16, 2018. Credit: Stellarium / Bob Trembley.Observing Target: Comet 46P/Wirtanen
Comet 46P/Wirtanen is within the orbit of Mars, and it is heading in our direction – it will pass within 11.5 million kilometers (30.23 lunar distances) of Earth – that’s REALLY close! It should be a fantastic observing target. BUT! It’s a comet… I can’t count the number of times I’ve see media prophecies of “Comet of the Year” fall flat. But I’ll sure HOPE it turns out being great – it’ll be visible for several months, so it’ll have a lot of time to be great!
Comet 46P/Wirtanen 10-16-2018. Credit: JPL Small Body Database BrowserComet 46P/Wirtanen currently looks like this:
Comet 46P/Wirtanen, October 7, 2018. Credit Yasushi AoshimaYou can find Comet 46P/Wirtanen low in the southern sky after midnight this week:
Position of Comet 46P/Wirtanen at midnight during the week of Oct. 16-22, 2018. Credit: Stellarium/ Bob TrembleyThe Moon
The Moon is a waxing crescent heading towards first quarter later on the 16th; for the rest of the week, the Moon will be a waxing gibbous, heading toward full. The Moon will be an excellent observing target this week, however it’s proximity to Mars and Saturn may wash those bodies out.
The Moon from Oct. 16-22, 2018. Visualizations by Ernie Wright.The Sun
SpaceWeather.com says that sunspot AR2725 is decaying – after squinting at a 4K hi-rez photosphere image, I sure couldn’t see anything remaining of it – BUT just look at the boiling region of coronal activity near the equator in the animation below!
A coronal hole has reopened up at the south pole, and the weeks-old north polar coronal hole remains; several smaller coronal holes appear in various locations.
A few small prominences have appeared on the Sun’s limb in the last couple days – if you look closely at this animation, you’ll see several pillar-type prominences pop-up and vanish in a single frame or two.
The solar wind speed is 534.8 km/sec, with a density of 2.2 protons/cm3.
Animated LASCO C2 Coronograph showing the solar corona above the Sun’s limb (the white circle).You can create your own time-lapse movies of the Sun here: AIA/HMI Browse Data.
You can browse all the SDO images of the Sun from 2010 to the present here: Browse SDO archive.
Asteroids
Upcoming Earth-asteroid encounters:
| Asteroid |
Date(UT)
|
Miss Distance
|
Velocity (km/s)
|
Diameter (m)
|
| 2018 SM2 |
2018-Oct-10
|
11.4 LD
|
10.1
|
89
|
| 2018 TC2 |
2018-Oct-10
|
16.4 LD
|
8.3
|
22
|
| 2018 TN3 |
2018-Oct-10
|
6.7 LD
|
7.3
|
8
|
| 2018 TS4 |
2018-Oct-11
|
5.2 LD
|
2.3
|
12
|
| 2018 TR4 |
2018-Oct-11
|
6.9 LD
|
11
|
36
|
| 2018 TD2 |
2018-Oct-12
|
12.9 LD
|
11.2
|
18
|
| 2018 TQ3 |
2018-Oct-12
|
10.5 LD
|
7.4
|
14
|
| 2018 TB5 |
2018-Oct-13
|
3.1 LD
|
16.3
|
17
|
| 2018 TC5 |
2018-Oct-13
|
12.6 LD
|
7.6
|
20
|
| 2018 TU4 |
2018-Oct-15
|
14.2 LD
|
11
|
28
|
| 2018 SL3 |
2018-Oct-15
|
9.1 LD
|
13.4
|
34
|
| 2018 TS1 |
2018-Oct-15
|
6.6 LD
|
10.9
|
27
|
| 2018 TZ2 |
2018-Oct-16
|
9.1 LD
|
16.7
|
41
|
| 2014 US7 |
2018-Oct-17
|
3.2 LD
|
8.7
|
19
|
| 2013 UG1 |
2018-Oct-18
|
10.4 LD
|
13.4
|
123
|
| 2016 GC221 |
2018-Oct-18
|
8.7 LD
|
14.4
|
39
|
| 2018 TT5 |
2018-Oct-24
|
15.9 LD
|
10.2
|
29
|
| 475534 |
2018-Oct-29
|
7.5 LD
|
18.1
|
204
|
| 2002 VE68 |
2018-Nov-04
|
14.7 LD
|
8.6
|
282
|
| 2018 TF3 |
2018-Nov-05
|
7.8 LD
|
20.6
|
310
|
| 2010 VQ |
2018-Nov-07
|
15.6 LD
|
3.8
|
10
|
| 2009 WB105 |
2018-Nov-25
|
15.2 LD
|
18.9
|
71
|
| 2008 WD14 |
2018-Nov-27
|
7.4 LD
|
9.3
|
93
|
| 2001 WO15 |
2018-Nov-28
|
13.6 LD
|
11.7
|
107
|
| 2013 VX4 |
2018-Dec-09
|
4.1 LD
|
6.6
|
65
|
| 2015 XX169 |
2018-Dec-13
|
17 LD
|
5.8
|
12
|
Notes: LD means “Lunar Distance.” 1 LD = 384,401 km, the distance between Earth and the Moon. Table from SpaceWeather.com
Near-Earth objects (NEOs) discovered this month: 100, this year: 1561, all time: 18959.
Potentially hazardous asteroids: 1936 (as of October 16, 2018)
Minor Planets discovered: 785,045 (as of October 9, 2018)
Orionids Meteor Shower
The Orionids are a medium strength shower that sometimes reaches high strength activity. In a normal year the Orionids produce 20-25 shower members at maximum. In exceptional years, such as 2006-2009, the peak rates were on par with the Perseids (50-75 per hour). At this time we are unable to predict exactly when the Orionids will be exceptional but there are theories that there may be a 12 year period in this cycle.
The Orionids are active from Sept. 23 – Nov. 27, and peak on Oct. 21-22.
Radiant: 06:20 +15.5° – ZHR: 25 – Velocity: 41 miles/sec (swift – 67km/sec) – Parent Object: Comet 1P/Halley
Orionids Meteor Shower Radiant. Credit: Stellarium / Bob Trembley.Interactive Visualization of Orionid Meteoroid Stream
[iframe src=’https://www.meteorshowers.org/view/iau-8′ percent=100]
Fireballs
On Oct. 15, 2018, the NASA All Sky Fireball Network reported 10 fireballs.
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point–Earth. Source: Spaceweather.comThe Solar System
This is the position of the planets and a couple spacecraft in the solar system – it amazes me how quickly the Parker Solar Probe has reached in-system, and Mars InSight is getting real close!
Position of the planets and several spacecraft in the inner solar system, Oct. 16, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.
Position of the planets in the middle solar system, Oct. 9, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.Spacecraft
Crew of Soyuz MS-10 Recovered Safely After Aborted Launch
A Speculative Timeline Regarding the Events of Soyuz MS-10’s Abort
Hubble Team Testing Anomalous Gyro
Mars InSight – Getting Closer
OSIRIS-REx Preforms Second Asteroid Approach Maneuver
Exoplanets
Confirmed Exoplanets: 3,793 (10/04/2018)
Multi-Planet Systems: 629 (10/04/2018)
Kepler Candidate Exoplanets: 4,717 (8/16/2018)
TESS Candidate Exoplanets: 44
-Data from the NASA Exoplanet Archive
Latest Exoplanet Discoveries: https://exoplanets.nasa.gov
Solar Week: Oct. 22-26
Solar Week is a week of online lessons, games and hands-on activities about the Sun for grades 5-9 or ages 9-14. Solar Week happens twice a year, approximately mid-to-late March and mid-to-late October.
Monday – The Sun As a Star
Tuesday – Solar Close-Ups
Wednesday- The Active Sun
Thursday – The Sky Above: Earth’s Upper Atmosphere
Friday – Solar Careers, Internships and Opportunities
Apps used for this post:
NASA Eyes on the Solar System: an immersive 3D solar system and space mission simulator – free for the PC /MAC.
I maintain the unofficial NASA Eyes Facebook page.
Stellarium: a free open source planetarium app for PC/MAC/Linux. It’s a great tool for planning observing sessions.
2018 is NASA’s 60th Anniversary!