Happy New Year!
The first day of 2019 is one for the record books – a spacecraft has flown-by the most distant object in the solar system to date, and another spacecraft has entered into orbit around an asteroid!
The Moon joins the multi-planet conjunction in the eastern predawn sky on the morning of Jan 1st.
Mercury, Jupiter, Venus and the Moon in the southeastern predawn sky – Jan. 1, 2019. Credit: Stellarium / Bob Trembley.The Moon will appear very near the planet Venus on the morning of Jan. 3rd.
Mercury, the Moon, Jupiter and Venus in the southeastern predawn sky – Jan. 3, 2019. Credit: Stellarium / Bob Trembley.Mars is high in southern sky after sunset all week; Mars continues to move slowly to the west and dim as the Earth pulls away from it in its orbit.
Mars remains high in the southern sky after sunset – Jan. 1, 2019. Credit: Stellarium / Bob Trembley.Altair and Vega are the first stars visible in the western sky at dusk.
The constellation Cassiopeia is high in the north-northwestern sky at 9:00 PM on Jan. 1st. Several other recognizable constellations are also in that direction.
Constellations in the north-northwestern sky at 9:00 PM on Jan. 1, 2019. Credit: Stellarium / Bob Trembley.
Today, the New Horizons spacecraft flew-by Kuiper belt object 2014 MU69, nicknamed “Ultima Thule.” This is the farthest object in the solar system that a robotic probe has flown-by – news of which eclipses any pretty Messier objects I’d like to show you this week. Images of 2014 MU69 will take agonizing days to transmit back to Earth.
It has been said that the New Horizons flyby of Pluto completed the initial reconnaissance phase of solar system exploration – but I’m not so sure that’s true, since the Parker Solar Probe just launched this year, and it’s the first mission to the Sun. Either way, this flyby is part of the earliest history of the second phase of solar system exploration, and the New Horizons spacecraft was played a part of both phases!
I wanted to give you the location of New Horizons in the sky, so you could go out, look up and point to it… but from Earth’s viewpoint, the New Horizons spacecraft is on the other side of the Sun – so don’t go look at that!
Position of the New Horizons spacecraft, Jan. 1, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.
The Moon is a waning crescent, visible low to the east before sunrise. The New Moon occurs on Jan 5th. After the 5th, the Moon will be a waxing crescent, visible toward the southwest in early evening.
The Sun has been spot-free for 16 days. The large coronal hole at the northern pole seems to have shrunk a bit, and the one at the south pole seems to have “filled-in” a bit. There is a large “>”shaped coronal hole long the the equator. SpaceWeather.com says “A large hole in the sun’s atmosphere is turning to face Earth and spewing a stream of solar wind in our direction. NASA’s Solar Dynamics Observatory photographed the structure on Dec. 31st.“
The last couple days had a lot of prominences! A beautiful, long-lasting, and large prominence can be seen in the lower-right side of the video below – WOW! Several smaller prominences can be see around the Sun’s limb.
The solar wind speed is 428.8 km/sec (↑), with a density of 5.5 protons/cm3 (↓).
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.
Upcoming Earth-asteroid encounters:
| Asteroid |
Date(UT)
|
Miss Distance
|
Velocity (km/s)
|
Diameter (m)
|
| 2018 XE4 |
2018-Dec-26
|
5.4 LD
|
9.4
|
18
|
| 2018 YL2 |
2018-Dec-27
|
0.2 LD
|
11.9
|
5
|
| 2018 YM2 |
2018-Dec-31
|
6.4 LD
|
11.3
|
42
|
| 2014 AD16 |
2019-Jan-04
|
12.9 LD
|
9.4
|
12
|
| 2018 XO4 |
2019-Jan-06
|
7.8 LD
|
4
|
31
|
| 2016 AZ8 |
2019-Jan-07
|
11.6 LD
|
9.1
|
224
|
| 2013 YM2 |
2019-Jan-09
|
7.3 LD
|
4.3
|
20
|
| 2018 XN |
2019-Jan-14
|
11.9 LD
|
5.6
|
59
|
| 2013 CW32 |
2019-Jan-29
|
13.9 LD
|
16.4
|
148
|
| 2013 RV9 |
2019-Feb-06
|
17.9 LD
|
5.9
|
68
|
| 2017 PV25 |
2019-Feb-12
|
7.3 LD
|
6.1
|
43
|
| 455176 |
2019-Feb-20
|
19.2 LD
|
26.5
|
269
|
| 2016 CO246 |
2019-Feb-22
|
15.8 LD
|
5.5
|
23
|
| 2018 DE1 |
2019-Feb-27
|
19.8 LD
|
6.5
|
28
|
| 2016 FU12 |
2019-Feb-27
|
15.4 LD
|
5.2
|
15
|
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: 0, this year: 0, all time: 19376 – Reset!
Potentially hazardous asteroids: 1947 (as of Dec. 26, 2018 – up from 1936)
Minor Planets discovered: 789,069 (as of Oct. 30, 2018)

On Dec. 31, 2018, the NASA All Sky Fireball Network reported 18 fireballs.
(15 sporadics, 2 December Leonis Minorids, 1 Quadrantid)
In this diagram of the inner solar system, all of the fireball orbits from Dec. 31, 2018 intersect at a single point–Earth. Source: Spaceweather.com
Comet 46P/Wirtanen – again… well, it’s still there!
Image credit: Flickr user: Ritzelmut.
Comet 46 P Wirtanen 2018-12-14 and 15 Telescope TS 71 F / 4.9 piggy back and guided with Telescope Lx200 GPS 16 ” F / 10 Camera Stl11000 C Resolution 5.30 “/ px Mosaic 5 paintings. Comet exhibition = 2 x90 seconds rest of the tables 2 x7 minutes. Processed and composition photoshop c6. Fasnia-Tenerife-Canary Islands by Quico Hernandez Cabrera
This is the position of the planets and a couple spacecraft in the solar system.
Position of the planets in the inner solar system, Jan. 1, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.
Position of the planets in the middle solar system, Jan. 1, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.I JUST found (and downloaded) this set of NASA posters of solar system objects – some objects have several different variations, they’re gorgeous!
This NASA poster set showcases the beauty of our solar system and beyond. Website links and an optional poster backs with orbit diagrams and context provide additional details and a deeper dive to explore our galactic neighborhood. Credit: NASA/JPL-Caltech.
New Horizons – Flew by Kuiper Belt object 2014 MU69
OSIRIS-REx – In orbit around asteroid Bennu
https://twitter.com/JimBridenstine/status/1078444781464891393

No change from last week – most likely due to the U.S. government being shutdown.
-Data from the NASA Exoplanet Archive
Apps used for this post:
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.
Stellarium: a free open source planetarium app for PC/MAC/Linux. It’s a great tool for planning observing sessions.
Section header image credits:
The Sky – Stellarium/ Bob Trembley
Observing Target – Turn Left at Orion / M. Skirvin
The Moon – NASA/JPL-Caltech
The Sun – NASA/JPL-Caltech
Asteroids – NASA/JPL-Caltech
Fireballs – Credited to YouTube
Comets –Comet P/Halley, March 8, 1986, W. Liller
The Solar System – NASA Eyes on the Solar System / Bob Trembley
Spacecraft News – NASA Eyes on the Solar System / Bob Trembley
Exoplanets – Space Engine / Bob Trembley







