I will be giving live demonstrations of NASA Eyes on the Solar System, Universe Sandbox, Kerbal Space Program and SpaceEngine at the Warren Public Library, Thursday August 22nd at 6:00 PM! I’ve given these demonstrations several times – I frequently hear “I had no idea these even existed!” from audience members. I lectured at this library a month ago, and mentioned I work for the VOF; afterwards, and audience member came up to me and showed me a picture on her phone of her with Br. Guy – taken overseas! Facebook event: [LINK].
Saturn and Jupiter continue to make excellent observing targets in the southern sky after sunset.
Saturn, Jupiter and Antares in the southern sky after sunset. Credit: Stellarium / Bob Trembley.By midnight, Saturn is high in the south-southwestern sky and Jupiter is near setting in the southwest.
Saturn and Jupiter in the southwestern sky at midnight on Aug. 20th. Credit: Stellarium / Bob Trembley.The eastern sky has some bright stars and the Pleiades star cluster at 3:00 AM.
The Pleiades, Aldebaran and several bright stars in the eastern sky at 3:00 AM this week. Credit: Stellarium / Bob Trembley.On Aug. 20th, the Moon is high and lonely in the sky from midnight to dawn.
A lonely Moon high in the southeastern sky at 3:00 AM on Aug. 20th. Credit: Stellarium / Bob Trembley.The Summer Triangle sets in the west before sunrise all week.
The Summer Triangle near setting in the west-northwestern predawn sky this week. Credit: Stellarium / Bob Trembley.Orion rises in the eastern predawn sky – a sure sign that fall is nearing.
Orion on the rise in the eastern predawn sky this week. Credit: Stellarium / Bob Trembley.Mercury continues to head away from us in its orbit, and appears lower each morning in the eastern predawn sky.
Mercury in the eastern predawn sky on Aug. 20, 2019. Credit: Stellarium / Bob Trembley.The Moon appears near the star Aldebaran in the eastern sky early in the morning from Aug. 23-26th – very near on the 24th!
Moon near Aldebaran in the early morning from Aug. 23-26th. Credit: Stellarium / Bob Trembley.
M 23
Messier 23. Credit: Wikisky.“Messier 23, also known as NGC 6494, is an open cluster of stars in the southern constellation of Sagittarius. It was discovered by Charles Messier on June 20, 1764. M23 can be found with binoculars or a modestly sized telescope. The cluster is positioned in front of “an extensive gas and dust network”, although it is unclear if there is an association between the two. It is located near the ecliptic and thus is subject to lunar occultations.
The cluster is located 2,050 light years away. Estimates for the number of cluster members range from 169 up to 414, with a directly-counted mass of 1,206 M☉; 1,332 M☉ by application of the virial theorem. The cluster is around 330 million years old with a near-solar metallicity of [Fe/H] = −0.04.The brightest component (lucida) is of magnitude 9.3. Five of the cluster members are candidate red giants, while the variable VV Sgr is a candidate asymptotic giant branch star.” – Wikipedia
Location of M 23 around 11:00 PM on Aug. 20, 2019. Credit: Stellarium / Bob Trembley.
The Moon is a waning gibbous, rising after sunset, visible high in the sky after midnight, and visible to the southwest after sunrise.
The third quarter Moon occurs on August 23rd, rising around midnight, visible to the south after sunrise.
After August 23rd, the Moon will be a waning crescent, visible low to the east before sunrise
The Moon from Aug. 20-26, 2019. Visualizations by Ernie Wright / NASA’s Scientific Visualization Studio.Moon News
The Sun has been spot-free for 13 days. The coronal holes at the Sun’s poles have remained open for months; the north hole has been huge for over a month!
https://www.facebook.com/photo.php?fbid=10217604697703017&set=gm.2607782549233073&type=1&theater
The solar wind speed is 406.2 km/sec (↓), with a density of 4.0 protons/cm3 (↑) at 1100 UT.
Animated LASCO C2 Coronograph showing the solar corona above the Sun’s limb (the white circle). Credit: NASA/JPL-CaltechYou 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.
Upcoming Earth-asteroid encounters:
| Asteroid |
Date(UT)
|
Miss Distance
|
Velocity (km/s)
|
Diameter (m)
|
| 2016 PD1 |
2019-Aug-26
|
11.3 LD
|
5.9
|
65
|
| 2002 JR100 |
2019-Aug-27
|
19.4 LD
|
8.4
|
49
|
| 2019 OU1 |
2019-Aug-28
|
2.7 LD
|
13
|
95
|
| 2019 OF2 |
2019-Sep-03
|
18.3 LD
|
10.7
|
53
|
| 2018 DE1 |
2019-Sep-03
|
12.7 LD
|
6.6
|
28
|
| 2019 GT3 |
2019-Sep-06
|
19.5 LD
|
13.6
|
227
|
| 2010 RM82 |
2019-Sep-13
|
18.2 LD
|
14.6
|
23
|
| 2013 CV83 |
2019-Sep-13
|
15.7 LD
|
13.1
|
62
|
| 504800 |
2019-Sep-14
|
13.9 LD
|
14.4
|
155
|
| 467317 |
2019-Sep-14
|
13.9 LD
|
6.4
|
389
|
| 2019 JF1 |
2019-Sep-16
|
11.2 LD
|
4.3
|
61
|
| 2018 FU1 |
2019-Sep-16
|
18.4 LD
|
4.7
|
16
|
| 2017 SL16 |
2019-Sep-21
|
7.9 LD
|
6.5
|
25
|
| 2017 SM21 |
2019-Sep-21
|
11.5 LD
|
9.6
|
20
|
| 523934 |
2019-Sep-24
|
10.9 LD
|
22.3
|
257
|
| 2017 KP27 |
2019-Sep-26
|
6.2 LD
|
4.8
|
25
|
| 2006 QV89 |
2019-Sep-27
|
18.1 LD
|
4.1
|
31
|
| 2018 FK5 |
2019-Oct-01
|
13.3 LD
|
10.5
|
8
|
| 2018 LG4 |
2019-Oct-02
|
13.8 LD
|
8.1
|
12
|
| 2017 TJ4 |
2019-Oct-05
|
13.5 LD
|
8.9
|
32
|
Notes: LD means “Lunar Distance.” 1 LD = 384,401 km, the distance between Earth and the Moon. Red highlighted entries are asteroids that either pass very close, or very large with high relative velocities to the Earth. Table from SpaceWeather.com
Near-Earth objects (NEOs) discovered this month: 49 (+14), this year: 1287 (+16), all time: 20673 (+15)
Potentially hazardous asteroids: 1983 (last updated May 8, 2019)
Minor Planets discovered: 796,635 (+94)
I noticed that the number of known asteroids is approaching 800,000 – I wondered when this milestone might happen. I used data from my previous posts – the trend-line shows 800K being crossed sometime near the end of September of this year! This same trend-line shows the 1,000,000 milestone being crossed in July of 2032, but that’s at the current rate of discovery – hopefully the discovery rate will have increased dramatically before then.
Asteroid Discovery Trendline. Credit: Bob Trembley
On Aug. 19, 2019, the NASA All Sky Fireball Network reported 48 fireballs.
(43 sporadics, 4 Perseids, 1 Northern delta Aquariid)
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point–Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). From: Spaceweather.comFireball & Meteor News
This is the position of the planets and a couple bodies in the solar system – I highlighted the asteroid Pallas:
Position of the planets and a couple spacecraft in the inner solar system, Aug. 20, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.
Position of the planets and a couple asteroids in the middle solar system, Aug. 20, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.
Orbit of Pallas showing inclination to the plane of the ecliptic, Aug. 20, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.
Inner Solar System Seen from Pallas, Aug. 20, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.
Hypothetical view of the Sun and Pleiades star cluster seen from above Pallas. The urge to superimpose the U.S.S. Enterprise orbiting Pallas in this pic is almost overwhelming! Credit: SpaceEngine / Bob Trembley.
Hypothetical view of the Sun from the cratered surface of Pallas. Credit: SpaceEngine / Bob Trembley.
Position of the planets and a couple spacecraft in the outer solar system – the orbit of Halley’s comet is highlighted, Aug. 20, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.NASA’s Interactive Real-Time Web-based Orrery:
[iframe src=’https://eyes.nasa.gov/apps/orrery/’ height=600 percent=100 style=””]
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