Comet C/2020 F3 (NEOWISE) continues to dominate astronomy news this week; VOF blogger Fr. James Kurzynski posted several beautiful comet pictures of his in an article on this site.
Comet NEOWISE appears in the northwestern evening sky before midnight all week.
The Moon appears in the western sky near dusk this week – it should make a great observing target by the weekend.
Jupiter and Saturn continue to make great late evening and early morning observing targets all week in the southern sky.
Mars continues to appear high in the southeastern predawn sky this week.
Venus appears near the star Aldebaran, and Mercury appears low above the horizon all week; Mercury reaches its highest point on July 23rd, and then starts back towards the horizon.
The new Moon occurred on Monday July 20th – the Moon is not visible at this time…
The Moon is now a waxing crescent – visible toward the southwest in early evening.
The first quarter Moon occurs on July 27th – it will be visible high in the southern sky in early evening.
Moon News
The Sun has been spotless for 10 days – it appears that a sunspot is emerging on the limb of the Sun in the lower left of the video. The northern coronal hole is now huge, while the southern hole remains small; more small coronal holes pepper the face of the Sun.
The Sun seen in 193 angstroms (extreme ultraviolet) July 20, 2020:
Medium prominence activity, with a really nice loop! Look closely at the lower left near the end of the video, and you’ll see the bright active region coming into view.
The Sun seen in 304 angstroms (extreme ultraviolet) July 20, 2020:
You can view the Sun in near real-time, in multiple frequencies here: SDO-The Sun Now.
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.
Facebook: SolarActivity – Run by Solar System Ambassador Pamela Skivak
https://www.facebook.com/photo.php?fbid=10222926025080027&set=gm.3377777782233542&type=3&theater&ifg=1
Sun News from SpaceWeather.com:
CME IMPACT POSSIBLE THIS WEEK: On July 19th, a faint, slow-moving CME left the sun. NOAA analysts believe the plasma cloud could graze Earth’s magnetic field on July 24th or 25th. A similar slow-moving CME hit Earth on July 13th, causing high-latitude auroras and a surprise visit from STEVE.
Solar Corona
Solar wind speed is 355.7 km/sec (↓), with a density of 4.2 protons/cm3 (↓) at 1305 UT.
Near real-time animation of the corona and solar wind from the Solar & Heliospheric Observatory (SOHO):
Potentially hazardous asteroids: 2037 (last updated June 2, 2020)
Total Minor Planets discovered: 989,213 (+11,914)
Upcoming Earth-asteroid encounters:
Asteroid |
Date(UT)
|
Miss Distance
|
Velocity (km/s)
|
Diameter (m)
|
2002 BF25 |
2020-Jul-21
|
9.4 LD
|
6.8
|
129
|
2020 NO |
2020-Jul-22
|
2 LD
|
7.6
|
16
|
2020 ON |
2020-Jul-23
|
13.6 LD
|
17.4
|
64
|
2020 ND |
2020-Jul-24
|
14.5 LD
|
13.6
|
153
|
2020 NN |
2020-Jul-25
|
16.3 LD
|
10.1
|
47
|
2020 NZ |
2020-Jul-28
|
8.2 LD
|
7.8
|
29
|
2020 MX3 |
2020-Jul-29
|
9.4 LD
|
8.5
|
66
|
2018 PY7 |
2020-Jul-31
|
8.9 LD
|
9.5
|
16
|
2007 RF1 |
2020-Jul-31
|
10.7 LD
|
5
|
21
|
2018 BD |
2020-Aug-03
|
7.6 LD
|
9.4
|
3
|
2009 PQ1 |
2020-Aug-05
|
10.8 LD
|
13.5
|
112
|
2020 FA1 |
2020-Aug-23
|
18.4 LD
|
1.9
|
20
|
2016 AH164 |
2020-Aug-26
|
15.7 LD
|
5.6
|
4
|
2011 ES4 |
2020-Sep-01
|
0.3 LD
|
8.2
|
30
|
465824 |
2020-Sep-06
|
19.4 LD
|
14
|
162
|
2012 RM15 |
2020-Sep-12
|
14.9 LD
|
9.8
|
45
|
2017 US |
2020-Sep-13
|
17.3 LD
|
5.9
|
21
|
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
On July 20, 2020, the NASA All Sky Fireball Network reported 7 fireballs.
((6 sporadics, 1 alpha Capricornid)
Fireball News
Position of the planets and a couple spacecraft in the inner solar system.
Position of the planets in the middle solar system:
Position of the planets some transneptunian objects in the outer solar system:
Highlight: Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine times that of Earth. It only has one-eighth the average density of Earth; however, with its larger volume, Saturn is over 95 times more massive. Saturn is named after the Roman god of wealth and agriculture; its astronomical symbol (♄) represents the god’s sickle.
Saturn’s interior is most likely composed of a core of iron–nickel and rock (silicon and oxygen compounds). Its core is surrounded by a deep layer of metallic hydrogen, an intermediate layer of liquid hydrogen and liquid helium, and finally a gaseous outer layer. Saturn has a pale yellow hue due to ammonia crystals in its upper atmosphere. An electrical current within the metallic hydrogen layer is thought to give rise to Saturn’s planetary magnetic field, which is weaker than the Earth’s, but has a magnetic moment 580 times that of Earth due to Saturn’s larger size. Saturn’s magnetic field strength is around one-twentieth of Jupiter’s. The outer atmosphere is generally bland and lacking in contrast, although long-lived features can appear. Wind speeds on Saturn can reach 1,800 km/h (1,100 mph; 500 m/s), higher than on Jupiter, but not as high as those on Neptune.
The planet’s most famous feature is its prominent ring system, which is composed mostly of ice particles, with a smaller amount of rocky debris and dust. At least 82 moons are known to orbit Saturn, of which 53 are officially named; this does not include the hundreds of moonlets in its rings. Titan, Saturn’s largest moon, and the second-largest in the Solar System, is larger than the planet Mercury, although less massive, and is the only moon in the Solar System to have a substantial atmosphere. – Wikipedia
There is an absolute TON more about Saturn in this Wikipedia article.
Saturn’s Moons
Saturn’s Moons. Credit: NASA/JPL/David SealSaturn has 82 known moons, 53 of which have formal names. In addition, there is evidence of dozens to hundreds of moonlets with diameters of 40–500 meters in Saturn’s rings, which are not considered to be true moons. Titan, the largest moon, comprises more than 90% of the mass in orbit around Saturn, including the rings. Saturn’s second-largest moon, Rhea, may have a tenuous ring system of its own, along with a tenuous atmosphere. – Wikipedia