In the Sky This Week – October 23, 2018
The constellations Leo and Ursa Major appear in the east-northeastern sky before sunrise; the bright star Regulus is hard to miss in the eastern sky.
The Constellations Leo and Ursa Major (including the "Big Dipper" asterism) are in the east-northeast predawn sky. Credit: Stellarium / Bob Trembley.
The constellations Orion and Taurus are high in the southwestern predawn sky.
The constellations Orion and Taurus are high in the southwestern sky before dawn. Credit: Stellarium / Bob Trembley.
Mars and Saturn are great observing targets this week; sadly, Saturn is getting lower in the southwestern sky each evening.
Mars high and Saturn a bit lower in the south-southern sky after sunset on Oct. 23, 2018. Credit: Stellarium / Bob Trembley.
The full and waning gibbous Moon will be visible nearly all night long this week - rising later in the east with each evening.
Position of the Moon in the early morning hours over the week of Oct. 23-29, 2018. Credit: Stellarium/ Bob Trembley
Jupiter and Mercury appear low in the southwestern sky at dusk - Mercury may be quite the challenge to see.
Jupiter and Mercury low in the southwestern sky at dusk on Oct. 23, 2018. Credit: Stellarium / Bob Trembley.
Observing Target: Conjunction of the Moon and Aldebaran
There will be an early morning conjunction of the Moon and the star Aldebaran on Oct. 27th.
Early morning conjunction of the Moon and the star Aldebaran in the constellation Taurus at 6:00 AM on Oct. 27, 2018; the Pleiades star cluster is nearby. Credit: Stellarium/ Bob Trembley
Comets
Appearing wider than the planet Jupiter, comet 46P/Wirtanen continues to make the news:
Comet 46P Wirtanen - Oct. 18, 2018. Credit: Rolando Ligustri
You can find Comet 46P/Wirtanen low in the southern sky after midnight this week - the Moon may wash it out quite a bit this week, tho...
Position of Comet 46P/Wirtanen Week of Oct. 23-29 2018. Credit: Stellarium/ Bob Trembley
Position of Comet 46P/ Wirtanen in the Solar System, Oct. 23, 2018. Credit: JPL Small Body Database / Bob Trembley
The Moon
The Moon is a waxing gibbous heading towards full on the 24th; for the rest of the week the Moon will be a waning gibbous. The Moon will visible all night long earlier this week, and well past dawn later in the week.
The Moon from Oct. 23-29, 2018. Visualizations by Ernie Wright.
The Sun
The sun has been spot-free for 5 days. The coronal hole that reopened at the south pole last week remains open, but is small compared to the several weeks-old north polar coronal hole; a couple small coronal holes appear near the equator - SpaceWeather.com says "Solar wind flowing from this large coronal hole could reach Earth on Oct. 24th." Something with a lot of coronal loop activity is rotating out of view on the Sun's limb.
As seems to be the case with this solar minimum, there are a couple relatively long-lasting prominences on the Sun's limb, and several small ones popping up and quickly disappearing.
The solar wind speed is 314.2 km/sec, with a density of 2.5 protons/cm3 - light and mild right now... let's see what the 24th brings...
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 UL |
2018-Oct-17
|
0.6 LD
|
5.8
|
5
|
| 2014 US7 |
2018-Oct-17
|
3.4 LD
|
8.7
|
19
|
| 2013 UG1 |
2018-Oct-18
|
10.5 LD
|
13.4
|
123
|
| 2018 UO1 |
2018-Oct-18
|
1.7 LD
|
20
|
12
|
| 2016 GC221 |
2018-Oct-18
|
8.7 LD
|
14.4
|
39
|
| 2018 UA |
2018-Oct-19
|
0 LD
|
14.1
|
3
|
| 2018 US1 |
2018-Oct-21
|
2.3 LD
|
7.1
|
14
|
| 2018 UH1 |
2018-Oct-24
|
5.3 LD
|
13
|
35
|
| 2018 TT5 |
2018-Oct-24
|
15.9 LD
|
10.2
|
29
|
| 2018 UE |
2018-Oct-25
|
17.3 LD
|
16.1
|
44
|
| 475534 |
2018-Oct-29
|
7.5 LD
|
18.1
|
204
|
| 2018 UC |
2018-Oct-30
|
5.4 LD
|
9.3
|
22
|
| 2002 VE68 |
2018-Nov-04
|
14.7 LD
|
8.6
|
282
|
| 2018 TF3 |
2018-Nov-05
|
7.8 LD
|
20.6
|
302
|
| 2010 VQ |
2018-Nov-07
|
15.6 LD
|
3.8
|
10
|
| 2018 UQ1 |
2018-Nov-14
|
9.5 LD
|
12.3
|
153
|
| 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
|
| 2018 TG6 |
2018-Dec-02
|
3.9 LD
|
1.4
|
13
|
| 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
2018 UA above was listed as passing at 0 Lunar Diameters - that seemed pretty close, so I looked it up - it passed within about 75,000 km:
Position of asteroid 2018 UA Oct. 19, 2018. Credit: JPL Small Body Database / Bob Trembley
Near-Earth objects (NEOs) discovered this month: 141, this year: 1602, all time: 19000.
Potentially hazardous asteroids: 1936 (as of October 23, 2018)
Minor Planets discovered: 785,045 (as of October 9, 2018)
Fireballs
On Oct. 22, 2018, the NASA All Sky Fireball Network reported 45 fireballs.
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. Source: Spaceweather.com
The Solar System
This is the position of the planets and a couple spacecraft in the solar system - the Parker Solar Probe is almost to the orbit of Mercury, and Mars InSight is continues to close-in on Mars.
Position of the planets and several spacecraft in the inner solar system, Oct. 23, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.
Position of the planets in the middle solar system, Oct. 23, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.
Inferior Conjunction of Venus
On Oct. 26th, Venus will pass almost directly between Earth and the Sun - this is known as an "Inferior Conjunction." As the conjunction approaches, the nighttime side of Venus is turned towards the Earth, and only a ... thin sliver of the planet is visible.
Venus, Oct. 20, 2018. Credit: Shahrin Ahmad
Spacecraft
Repair Work on Hubble Continues
The rotation rates produced by the backup gyro have reduced and are now within a normal range. Additional tests to be performed to ensure Hubble can return to science operations with this gyro. For more info: https://t.co/lT2Wpycqw2
— Hubble (@NASAHubble) October 22, 2018
Mars InSight CubeSat Attendant Spots Mars
The Pale Red Dot
Here’s the first picture of #Mars taken by a CubeSat, thanks to our tiny #MarCO spacecraft, currently traveling to the planet behind @NASAInSight: https://t.co/ZdzfLL3eYu pic.twitter.com/332N1Ysldi— NASA JPL (@NASAJPL) October 22, 2018
OSIRIS-REx Update
Today marks the 775th day that I have been in space. 🗓 I'm now about 131 million kilometers (81 million miles) from Earth, and it takes about 15 minutes round-trip to communicate with the team on the ground.🌍
More about my progress: https://t.co/rACre4nDe4 pic.twitter.com/75wohkGnLI
— NASA's OSIRIS-REx (@OSIRISREx) October 22, 2018
Exoplanets
Confirmed Exoplanets: 3,798 (10/11/2018)
Multi-Planet Systems: 630 (10/11/2018)
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!