Mars, Saturn, Antares and Jupiter are splashed across the southern predawn sky.
Southern sky at 5:30 AM, Apr. 24, 2018, with constellations. Credit: Stellarium / Bob Trembley.Over the next year and a half, Jupiter will slowly make its way closer to Saturn; From Earth’s perspective, Jupiter and Saturn will appear near each other in the sky for the next several years.
Southern sky at 5:30 AM, Apr. 17, 2018, showing path Jupiter will take over the next several months. Credit: Stellarium / Bob Trembley.Venus is low in the western sky near sunset; Venus is catching up to Earth in its orbit (see Inner Solar System image below), and will remain in the western sky at dusk until the end of September.
Western sky at 8:30 PM, Apr. 24, 2018, showing Venus’ orbit. Credit: Stellarium / Bob Trembley.The constellation Gemini can be seen above Orion, which is setting in the west shortly after sunset.
Western sky at 10:00 PM, Apr. 24, 2018 with Gemini above a setting Orion. Credit: Stellarium / Bob Trembley.The Moon will be near the star Regulus in Leo on April 25th around midnight.
Western sky at 1:00 AM, Apr. 25, 2018 with the Moon near Regulus. Credit: Stellarium / Bob Trembley.
The Moon
The Moon Apr. 24-30, 2018 2018. Visualizations by Ernie WrightThe Moon is a waxing gibbous heading towards full on the 30th – the next few days will be great for doing some sidewalk astronomy!
While I was at the NASA website where I get these Moon images, there was a sidebar item highlighting the new and improved NASA’s Lunar Reconnaissance Orbiter (LRO) Tour of the Moon video. I’ve shown an older version of this video many times as part of my Moon lecture – this version is spectacular! Teachers take note!
The Sun
The Sun has a medium-sized sunspot, which has been rotating towards the Earth for the last several days.
This sunspot appears unremarkable, until you see it in extreme ultraviolet! There is an enormous amount of coronal activity, and some beautiful coronal loops associated with this sunspot. SpaceWeather.com says: “Sunspot AR2706 has a stable magnetic field that poses no threat for strong solar flares.”
There are coronal holes at both of the Sun’s poles; the solar wind speed is 350 km/sec, with a density of 5.0 protons/cm3. SpaceWeather.com says: “A stream of solar wind is approaching Earth and it could graze our planet’s magnetic field on April 26th. The gaseous material is flowing from a northern hole in the sun’s atmosphere. The stream won’t hit our planet head on, but sometimes grazing impacts produce interesting effects–for instance, making Earth’s magnetosphere ring like a bell.”
The Sun’s chromosphere had a several small prominences over the last couple days – what’s really interesting is how the activity of sunspot AR2706 looks totally different at the frequency shown in the image below.
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 GH |
2018-Apr-25
|
14.6 LD
|
10.7
|
89
|
| 2018 HP |
2018-Apr-26
|
11.6 LD
|
10.3
|
20
|
| 2018 GH5 |
2018-Apr-27
|
12.2 LD
|
12.7
|
32
|
| 2018 GB2 |
2018-Apr-27
|
17.1 LD
|
14.6
|
92
|
| 2013 US3 |
2018-Apr-29
|
10.1 LD
|
7.7
|
214
|
| 2018 GO4 |
2018-Apr-29
|
11.8 LD
|
8.6
|
46
|
| 2018 GY1 |
2018-Apr-29
|
13.2 LD
|
16.7
|
141
|
| 2018 FV4 |
2018-Apr-29
|
17.7 LD
|
6.5
|
59
|
| 2002 JR100 |
2018-Apr-29
|
10.8 LD
|
7.7
|
49
|
| 2018 HB1 |
2018-May-02
|
10.2 LD
|
9.2
|
39
|
| 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
|
| 2018 GR2 |
2018-May-11
|
13.4 LD
|
9.8
|
109
|
| 1999 LK1 |
2018-May-15
|
13.3 LD
|
10
|
141
|
| 2018 GL1 |
2018-May-18
|
14.3 LD
|
5.2
|
67
|
| 68347 |
2018-May-29
|
9.5 LD
|
13.3
|
389
|
| 2013 LE7 |
2018-May-31
|
17.8 LD
|
1.7
|
12
|
| 2018 EJ4 |
2018-Jun-10
|
5.6 LD
|
6.2
|
195
|
| 2015 DP155 |
2018-Jun-11
|
9 LD
|
4.4
|
170
|
| 2017 YE5 |
2018-Jun-21
|
15.6 LD
|
15.5
|
513
|
Notes: LD means “Lunar Distance.” 1 LD = 384,401 km, the distance between Earth and the Moon. Table from SpaceWeather.com
Near-Earth objects discovered this month: 122, this year: 609, all time: 18160. As of April 17, 2018 there are 1907 known potentially hazardous asteroids.
Meteor Showers
The Lyrids Meteor shower peaked on the evening of April 21-22, but runs until April 25 – you might still be able to catch a few meteors from this shower.
Lyrids Meteor Shower Radiant. Credit: StellariumFireballs
On Apr 23, 2018, the NASA All Sky Fireball Network reported 26 fireballs.
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point–Earth.The Solar System
This is the position of the planets in the solar system:
Position of the planets in the inner solar system, Apr. 24, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.
Position of the planets in the middle solar system, Apr. 24, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.
Position of the planets in the outer solar system, Apr. 24, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.
Position of the planets in the inner solar system, Apr. 24, 2018 – side 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.
