This week, Mars whips past Saturn in the southern predawn sky; the conjunction of the two planets will last into next week. The Moon joins the morning planets after the weekend.
Southern predawn sky, Mar. 27-Apr.8 2018. Credit: Stellarium / Bob Trembley.Mercury has vanished into the glare of the Sun, but Venus is still low in the western sky after sunset all week long.
Venus low in the western sky shortly after sunset, Mar. 270, 2018. Credit: Stellarium / Bob Trembley.Shortly after sunset, the winter constellations Orion and Taurus are visible in the southwestern sky.
Western sky after sunset, Mar. 27, 2018. Credit: Stellarium / Bob Trembley.I use Stellarium to generate many of the sky images in this post series; a new version of the app was released on March 25th. One REALLY COOL feature in the new version is the ability to map data from dozens of different sky surveys onto the night sky. The image below shows far-infrared data from the European Space Agency’s Akari space telescope. When I brought this image up on my computer, I sat there staring at my screen in dumbfounded amazement. I thought: “I’m seeing the Interstellar Medium” – the clouds of gas and dust that our Sun, and all the stars of the Milky Way drift through. Just WOW!
Western sky with data mapped from the Akari Far-Infrared All-Sky Survey. Credit: Stellarium / Bob Trembley.The Moon
The Moon Mar. 27-Apr. 2 2018. Visualizations by Ernie WrightThe Moon is a waxing gibbous heading towards full this weekend. Afterwards the Moon will be a waning gibbous, visible late in the evening and setting shortly after dawn.
The Sun
The Sun has been spot-free for 8 days. There are coronal holes at both the Sun’s poles.
The solar wind speed is 535km/sec, with a density of 5.0 protons/cm3. SpaceWeather.com says “Solar wind flowing from the indicated coronal hole is expected to reach Earth on March 30.”
The Sun’s chromosphere had several small prominences over the last couple days.
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 DH1 |
2018-Mar-27
|
9.2 LD
|
14.4
|
224
|
| 2016 SR2 |
2018-Mar-28
|
18.7 LD
|
7.3
|
20
|
| 2018 FU1 |
2018-Mar-28
|
12.3 LD
|
5.9
|
15
|
| 2018 FO4 |
2018-Mar-28
|
7.7 LD
|
6.3
|
11
|
| 2018 FU3 |
2018-Mar-29
|
17.7 LD
|
8.4
|
20
|
| 2018 FE4 |
2018-Mar-29
|
13.3 LD
|
20.7
|
35
|
| 2018 FB |
2018-Mar-29
|
4.9 LD
|
8.5
|
57
|
| 2018 FB2 |
2018-Mar-30
|
10 LD
|
6.7
|
26
|
| 2010 GD35 |
2018-Mar-31
|
15.5 LD
|
11.6
|
45
|
| 2018 EM4 |
2018-Apr-01
|
6.2 LD
|
6.2
|
31
|
| 2004 FG29 |
2018-Apr-02
|
4 LD
|
14.9
|
22
|
| 2018 ER1 |
2018-Apr-02
|
15.6 LD
|
4
|
26
|
| 2018 EB |
2018-Apr-04
|
10.4 LD
|
15.1
|
165
|
| 2018 FW4 |
2018-Apr-05
|
9.8 LD
|
11.6
|
32
|
| 363599 |
2018-Apr-12
|
19.3 LD
|
24.5
|
224
|
| 2014 UR |
2018-Apr-14
|
9.3 LD
|
4.4
|
17
|
| 2016 JP |
2018-Apr-20
|
12 LD
|
12.7
|
214
|
| 2012 XL16 |
2018-Apr-23
|
15.8 LD
|
6.1
|
28
|
| 2013 US3 |
2018-Apr-29
|
10.1 LD
|
7.7
|
214
|
| 2018 FV4 |
2018-Apr-29
|
17.7 LD
|
6.5
|
61
|
| 2002 JR100 |
2018-Apr-29
|
10.8 LD
|
7.7
|
49
|
| 1999 FN19 |
2018-May-07
|
9.7 LD
|
5.7
|
118
|
| 2016 JQ5 |
2018-May-08
|
6.3 LD
|
10.4
|
9
|
| 388945 |
2018-May-09
|
6.5 LD
|
9
|
295
|
| 1999 LK1 |
2018-May-15
|
13.3 LD
|
10
|
141
|
Notes: LD means “Lunar Distance.” 1 LD = 384,401 km, the distance between Earth and the Moon. Table from SpaceWeather.com
As of March 20, 2018 there are 1882 known potentially hazardous asteroids.
Fireballs
On Mar. 26, 2018, the NASA All Sky Fireball Network reported 6 fireballs.
The category of fireballs this week includes China’s Tiangong-1 space station, which will re-enter the atmosphere and burn-up sometime between March 30th and April 2nd, somewhere in the green shaded area below:
Tiangong-1 reentry area. Credit: ESA
Tiangong-1 Reentry simulated in Kerbal Space Program. Credit: Bob TrembleyTo see a live tracking map of Tiangong-1 click here: [Link]
The Solar System
This is the position of the planets in the solar system:
Position of the planets in the solar system, Mar. 27, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.
Position of the planets in the solar system, Mar. 27, 2018 – alternate view. Credit: NASA Eyes on the Solar System / Bob Trembley.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.
