In the Sky This Week – October 30, 2018

The Moon will appear low in the eastern sky between the constellations Gemini and Orion during the early morning hours on Oct. 30^th.

The Moon will be between the constellations Gemini and Orion in the early morning east-southeastern sky on Oct. 30th. Credit: Stellarium / Bob Trembley.

That same Moon will appear high in the sky as dawn’s light begins to show.

The Moon and the constellations Gemini and Orion are high in the southwest predawn sky on Oct. 30th. Credit: Stellarium / Bob Trembley.

There will be a conjunction of the crescent Moon and the star Regulus low in the eastern sky, early in the morning hours on Nov. 2^nd.

Conjunction of the Moon and the star Regulus in the early morning sky, Nov. 2nd. Credit: Stellarium / Bob Trembley.

A very thin crescent Moon will appear with the star Arcturus in the eastern predawn sky on Nov. 5^th.

A thin waning crescent moon and the bright star Arcturus in the eastern predawn sky, Nov. 5th. Credit: Stellarium / Bob Trembley.

Mars and Saturn continue to put on a show in the southern sky after sunset.

Mars and Saturn in the south-southern sky after sunset on Oct. 30th. Credit: Stellarium / Bob Trembley.

Observing Target: The Dance of the Planets

Over the next week, the positions of Jupiter and Mercury change drastically in southwestern sky at dusk! Mercury stays low but gets brighter – Jupiter makes a quick dive towards the horizon, and will soon to be hidden by the glare of the Sun.

Animation of Mercury and Jupiter in the southwestern sky near sunset Oct. 29-Nov. 7

Comets

Comet 46P/Wirtanen in the news:

Comet 46P/Wirtanen & IC 1762, Oct. 29, 2018. Credit: Piotr Dzikowski

You can find Comet 46P/Wirtanen in the southern sky after midnight this week.

Position of Comet 46P Wirtanen Oct. 30-Nov. 6 2018. Credit: Stellarium / Bob Trembley.

The Moon

The Moon is a waning gibbous heading towards third-quarter on Oct. 31^st; after Halloween, the Moon will be a waning crescent. As I saw my wife off to school this morning, predawn light was just starting brighten the sky, and the Moon was nearly directly overhead.

The Moon from Oct. 30-Nov. 5, 2018. Visualizations by Ernie Wright.

The Sun

The sun has been spot-free for 12 days. Coronal holes remain open at both poles, and a rather large hole with a smaller companion appear on the equator.  SpaceWeather.com says “A stream of solar wind flowing from a small hole in the sun’s atmosphere is approaching Earth. Estimated time of arrival: Oct. 31st. The gaseous material could create ghostly-green skies around the Arctic Circle for Halloween.” There doesn’t appear to be any bright regions of coronal loop activity, but there may be something rotating into view on the Sun’s limb.

As with last week, there are a couple relatively long-lasting prominences on the Sun’s limb, and multiple short-lived ones popping up and quickly disappearing; have a close look at the northern limb in the animation below where dozens of small prominences are doing this.

The solar wind speed is 310.9 km/sec, with a density of 10.4 protons/cm³.

Animated LASCO C2 Coronograph showing the solar corona above the Sun’s limb (the white circle).

Asteroids

Upcoming Earth-asteroid encounters:

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: 151, this year: 1613, all time: 19011.
Potentially hazardous asteroids: 1936 (as of October 30, 2018)
Minor Planets discovered: 789,069 (as of October 30, 2018)

Fireballs

On Oct. 29 2018, the NASA All Sky Fireball Network reported 30 fireballs.

In this diagram of the inner solar system, all of the fireball orbits from Oct. 29, 2018 intersect at a single point–Earth. Source: Spaceweather.com

The Solar System

This is the position of the planets and a couple spacecraft in the solar system – the Parker Solar Probe has passed the orbit of Mercury!

Position of the planets and several spacecraft in the inner solar system, Oct. 30, 2018. The Parker Solar Probe has crossed the orbit of Mercury, making it the closest a spacecraft has ever come to the Sun. Credit: NASA Eyes on the Solar System / Bob Trembley.

Position of the planets in the middle solar system, Oct. 30, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.

Interesting Solar System News

Spacecraft

Hubble Space Telescope Back Online!

Parker Solar Probe Sets Two Records!

OSIRIS-REx Update

Exoplanets

Confirmed Exoplanets: 3,826 (10/26/2018)
Multi-Planet Systems: 633 (10/26/2018)
Kepler Candidate Exoplanets: 4,717 (8/16/2018)
TESS Candidate Exoplanets: 44
-Data from the NASA Exoplanet Archive
Latest Exoplanet Discoveries: https://exoplanets.nasa.gov

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.

2018 is NASA’s 60th Anniversary!