The Apollo 11 50th anniversary is itself now a part of history – the hashtag #Apollo50th was trending on social media. One of the coolest things I saw on the news was the Washington Monument being used as a projection screen for an animation of the Apollo 11 launch and mission – the celebration drew a veritable horde of attendees to the National Mall.
[tweet https://twitter.com/thehill/status/1152428219330637824 width=’400′ align=’left’][tweet https://twitter.com/nasahqphoto/status/1152439201817870337 width=’400′ align=’left’]
The star Arcturus continues to be the evening star the western sky after sunset.
The star Arcturus in the western sky around midnight on July 23rd. Credit: Stellarium / Bob Trembley.Saturn is high and Jupiter is low in the southwestern sky around midnight all week.
Saturn high and Jupiter low in the south-southwestern sky around midnight on July 23rd. Credit: Stellarium / Bob Trembley.The Moon will appear near the star Aldebaran in the Eastern sky early in the morning on July 27th & 28th.
The Moon will continue to appear closer to the eastern horizon with each morning; I’ll be watching for it out my kitchen window as I make my morning coffee. I wonder if I’ll be able to see the waning crescent Moon from our new home – wherever that may be…
The Moon appears low in the eastern sky early in the morning on July 29th. Credit: Stellarium / Bob Trembley.
M11 – Wild Duck Cluster
M 11 – The Wild Duck Cluster. Credit: RawAstroData.com.The Wild Duck Cluster (also known as Messier 11, or NGC 6705) is an open cluster of stars in the southern constellation of Scutum. It was discovered by Gottfried Kirch in 1681. Charles Messier included it in his catalogue of diffuse objects in 1764. Its name derives from the brighter stars forming a triangle which could resemble a flying flock of ducks (or, from other angles, one swimming duck). The cluster is located just to the east of the Scutum Star Cloud midpoint.
The Wild Duck Cluster is one of the richest and most compact of the known open clusters. It is one of the most massive open clusters known, and it has been extensively studied. Its age has been estimated to about 316 million years. The core radius is 1.23 pc while the tidal radius is 29 pc. Estimates for the cluster mass range from 3,700 M☉ to 11,000 M☉, depending on the method chosen… – Wikipedia
Location of M 11 – July 23 2019 2030. 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 July 25th, it rises around midnight, and is visible to the south after sunrise.
After July 25th, the Moon will be a waning crescent, visible low to the east before sunrise.
The Moon from July 23-29, 2019. Visualizations by Ernie Wright / NASA’s Scientific Visualization Studio.Moon News
Rik Hill is now posting his astrophotos of the Moon on the Sacred Space Astronomy blog! Rik is a frequent poster on Facebook’s Moon Photography group.
The Sun has a very small spot that was briefly visible but is fading – I can’t spot it on any of the most recent HMI images, but it’s magnetic activity is clearly visible as bright regions on the equator in the two videos below. SpaceWeather.com says “AR2745 poses no threat for strong solar flares. Its magnetic polarity identifies it as a member of old Solar Cycle 24.” Large coronal holes continue to appear at both poles.
A long-lived pillar prominence on one limb, and a couple very photogenic prominences on the Sun’s other limb made for excellent targets for solar observers!
https://www.facebook.com/photo.php?fbid=10217400956329610&set=gm.2558840744127254&type=3&theater&ifg=1
The solar wind speed is 382.9 km/sec (↑), with a density of 0.8 protons/cm3 (↓).
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)
|
| 2015 HM10 |
2019-Jul-24
|
12.2 LD
|
9.5
|
68
|
| 2019 OD |
2019-Jul-24
|
0.9 LD
|
19.2
|
70
|
| 2019 OE |
2019-Jul-24
|
2.5 LD
|
9.1
|
31
|
| 2010 PK9 |
2019-Jul-26
|
8.2 LD
|
16.5
|
155
|
| 2019 NT1 |
2019-Jul-27
|
19 LD
|
3.7
|
14
|
| 2019 NN4 |
2019-Jul-29
|
6.6 LD
|
3.8
|
26
|
| 2006 QQ23 |
2019-Aug-10
|
19.4 LD
|
4.7
|
339
|
| 454094 |
2019-Aug-12
|
17 LD
|
8.2
|
148
|
| 2018 PN22 |
2019-Aug-17
|
17.1 LD
|
2.3
|
11
|
| 2016 PD1 |
2019-Aug-26
|
11.4 LD
|
5.9
|
65
|
| 2002 JR100 |
2019-Aug-27
|
19.4 LD
|
8.4
|
49
|
| 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
|
Notes: LD means “Lunar Distance.” 1 LD = 384,401 km, the distance between Earth and the Moon. Table from SpaceWeather.com
Potentially hazardous asteroids: 1983 (last updated May 8, 2019)
Minor Planets discovered: 796,432 (+16)
On July 22, 2019, the NASA All Sky Fireball Network reported 19 fireballs.
(18 sporadics, 1 alpha Capricornid)
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:
https://twitter.com/exossorg/status/1152394726508814337
This is the position of the planets and a couple bodies in the solar system:
Pan, Moon of Saturn
Pan, the innermost of Saturn’s known moons, has a mean radius of 8.8 miles (14.1 kilometers) and orbits 83,000 miles (134,000 kilometers) away from Saturn, within the Encke Gap of Saturn’s A-ring. As it orbits Saturn every 13.8 hours, it acts as a shepherd moon and is responsible for keeping the Encke Gap open. The gap is a 200 mile (325 kilometer) opening in Saturn’s A ring.
Pan creates stripes, called “wakes,” in the ring material on either side of it. Since ring particles closer to Saturn than Pan move faster in their orbits, these particles pass the moon and receive a gravitational “kick” from Pan as they do. This kick causes waves to develop in the gap and also throughout the ring, extending hundreds of miles into the rings. These waves intersect downstream to create the wakes, places where ring material has bunched up in an orderly manner thanks to Pan’s gravitational kick.
Pan, like Saturn’s moon Atlas, has a prominent equatorial ridge that gives it a distinctive flying saucer shape. – NASA Solar System Exploration
I was playing around in SpaceEngine, and these screen shots of Pan were just too good not to share!
These two images from NASA’s Cassini spacecraft show how the spacecraft’s perspective changed as it passed within 15,300 miles (24,600 kilometers) of Saturn’s moon Pan on March 7, 2017. This was Cassini’s closest-ever encounter with Pan, improving the level of detail seen on the little moon by a factor of eight over previous observations. Image Credit: NASA/JPL-Caltech/Space Science Institute
OSIRIS-REx Asteroid Sample Return Mission
OSIRIS-REx Asteroid Sample Return Mission orbiting close to asteroid Bennu, July 23, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.India is on Their way to the Moon!
Chinese Tiangong-2 Space Station Reenters over South Pacific Ocean
Landsat
Climate
Data from the NASA Exoplanet Archive
Exoplanet Artwork by Bob Trembley
Simulation of a volcano on the smaller planet of a hypothetical double-planet system orbiting the star Menkent. Credit: SpaceEngine / Bob Trembley
Hubble Pic: Spiral Galaxy NGC 3169
https://twitter.com/HUBBLE_space/sta
