Fall stars have appeared in the eastern predawn skies; the constellation Orion is low in the east, a thin waning crescent Moon near it for the next few days. Over the coming weeks, Orion will appear a bit higher each morning as it moves slowly towards the southeast.
Mars and Saturn continue to be a great observing targets in the southern skies for weeks to come!
Jupiter crawls slowly westward as the Earth continues to pull away from the giant planet; Jupiter will continue to dim over the next several weeks, and will set earlier each evening.
Venus is catching up with the Earth, and appears lower each evening in the western sky at dusk. The current half-phase of Venus is quite obvious in telescopes.
Southern Hemisphere:
From Buenos Aires, Argentina, the waning crescent Moon and Orion appear in the east-northeastern sky predawn sky. The Moon and Orion appear flipped from how I see them in Michigan – the Moon appearing as it does to me in a waxing crescent phase at dusk in the west.
On overhead view from Buenos Aires after dusk is simply a spectacular splash of planets across a sky bisected by the disk of the galaxy. Seeing the sky from the southern hemisphere is high on my “bucket list.”
The Moon
The Moon is a waning crescent visible in the eastern predawn sky. The Moon will be new on August 11th, and will return as a waxing crescent, visible in the western sky at dusk later in the week.
Observing Target: Jupiter
Jupiter won’t be around much longer, so catch a glimpse of it now while you can! I’ve shown Jupiter to many people in recent weeks – it’s always a treat!
At a recent meeting of the Warren Astronomical Society, a member mentioned seeing a dark storm in the northern latitudes.
The Hubble Space Telescope has imaged Jupiter and its moons many times over the couple decades
NASA’s Juno mission is in orbit of Jupiter; citizen scientists have been processing raw data returned from Juno and producing some truly spectacular images:
The Perseid Meteor Shower
“The Best Meteor Shower of the Year“™ happens this week. The Perseid meteor shower happens on August 12th. Observatories, museums and venues around the planet will be hosting star parties. Here’s hoping you catch a nice fireball!
The Sun
The Sun as been spot-free for 4 days – two active regions with coronal loop activity are facing Earth. The huge coronal hole at the north pole from last week remains, and a couple small equatorial holes are near the center of the Sun’s disk
The solar wind speed is 362.4 km/sec, with a density of 26.2 protons/cm3 that’s the thickest I’ve seen the wind!
SpaceWeather.com says: “The sun has been without sunspots for 38 of the past 41 days. To find a similar stretch of blank suns, you have to go back to 2009 when the sun was experiencing the deepest solar minimum in a century. Solar minimum has returned, bringing extra cosmic rays, long-lasting holes in the sun’s atmosphere, and strangely pink auroras.”
There appear to be small prominences all over the Sun the last couple days; one active region will soon be rotating out of view as another, larger one rotates into view.
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 OZ |
2018-Aug-06
|
7 LD
|
9.7
|
37
|
2018 PC |
2018-Aug-06
|
12.1 LD
|
9.3
|
54
|
2018 LQ2 |
2018-Aug-27
|
9.4 LD
|
1.5
|
39
|
2016 GK135 |
2018-Aug-28
|
16.8 LD
|
2.8
|
9
|
2016 NF23 |
2018-Aug-29
|
13.3 LD
|
9
|
93
|
1998 SD9 |
2018-Aug-29
|
4.2 LD
|
10.7
|
51
|
2018 DE1 |
2018-Aug-30
|
15.2 LD
|
6.5
|
28
|
2001 RQ17 |
2018-Sep-02
|
19.3 LD
|
8.3
|
107
|
2015 FP118 |
2018-Sep-03
|
12.3 LD
|
9.8
|
490
|
2017 SL16 |
2018-Sep-20
|
8.5 LD
|
6.4
|
25
|
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: 1, this year: 973, all time: 18525.
Potentially hazardous asteroids: 1912 (as of July 31, 2018)
Minor Planets discovered: 779,736 (as of July 31, 2018)
Fireballs
On Aug. 6, 2018, the NASA All Sky Fireball Network reported 75 fireballs.
The Solar System
This is the position of the planets and a couple spacecraft in the solar system:
Exoplanets
Confirmed Exoplanets: 3,774 (7/19/2018)
Multi-Planet Systems: 625 (7/19/2018 )
Kepler Candidate Exoplanets: 4,496 (8/31/2017)
TESS Candidate Exoplanets: 0
Data from the NASA Exoplanet Archive
Apps used for this post:
Stellarium: a free open source planetarium app for PC/MAC/Linux. It’s a great tool for planning observing sessions.
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.