In the Sky This Week – October 1, 2019

Saturn, Jupiter and the Moon will be excellent sidewalk astronomy targets all week.

Waxing crescent Moon low on the horizon with Jupiter and Saturn in the southwestern sky after sunset on Oct. 1, 2019. Credit: Stellarium / Bob Trembley

The Moon appears near both Jupiter and Saturn during this week.

The Moon leaves Saturn and Jupiter behind by the beginning of next week, but this sky is still great for doing observing sessions!

The Moon, Saturn and Jupiter across the southern sky after sunset on Oct. 7, 2019. Credit: Stellarium / Bob Trembley

Mars emerges from the glare of the Sun and appears low in the eastern predawn sky just before sunrise.

Mars very low in the eastern predawn sky, Oct. 1, 2019. Credit: Stellarium / Bob Trembley

The Pleiades are high (and hard to miss) in the eastern predawn sky.

The bright stars Capella, Aldebaran and the Pleiades star cluster in the eastern predawn sky Oct. 1, 2019. Credit: Stellarium / Bob Trembley

The constellation Cassiopeia appears in the northwestern predawn sky, and in the northeastern sky after sunset.

M103 – Open Star Cluster in Cassiopeia

Messier 103 (also known as M103, or NGC 581) is an open cluster where a few thousand stars formed in the constellation Cassiopeia. This open cluster was discovered in 1781 by Charles Messier‘s friend and collaborator Pierre Méchain. It is one of the most distant open clusters known, with distances of 8,000 to 9,500 light-years from the earth and ranging about 15 light-years apart. There are about 40 member stars within M103, two of which have magnitudes 10.5, and a 10.8 red giant, which is the brightest within the cluster. Observation of M103 is generally dominated by the appearance of Struve 131, though the star is not a member of the 172-star cluster. M103 is about 25 million years old. – Wikipedia

Messier 103. Credit: Bill McSorley / Sky at Night

There are quite a few deep-sky objects in Cassiopeia.

Deep sky objects in the constellation Cassiopeia. Credit: Stellarium / Bob Trembley

Infrared light reveals wispy lanes of gas and dust in Cassiopeia.

The northeastern sky seen in far infrared from the AKARI Far-Infrared All-Sky Survey. Color composition: (blue: N60; green: WideS; red: WideL). AKARI FIS All-Sky Survey HEALPIX map produced by the Centre d’Analyse de Donees Etendues (CADE) with the original processed data from ISAS/JAXA. See http://www.ir.isas.jaxa.jp/AKARI/Archive/Images/FIS_AllSkyMap/Doi_AKARI_FIR_AllSkySurvey.pdf
Source: Stellarium, Edited by: Bob Trembley

The Moon is a waxing crescent, visible toward the southwest in early evening.

The first-quarter Moon occurs on Saturday October 5^th, it will be visible high in the southern sky in early evening – great for sidewalk astronomy!

After October 5^th, the Moon will be a waxing gibbous, visible to the southeast in early evening, and up for most of the night.

The Moon from Oct. 1-7, 2019. Visualizations by Ernie Wright / NASA’s Scientific Visualization Studio.

Moon News

The Sun has an emerging spot! As of this writing, the spot has not been assigned an Active Region (AR) number.

The northern coronal hole continues to be ginormous, and the southern hole seems to have reopened. A moderate-sized coronal hole also appears below the equator.

Sun in 193 angstroms (extreme ultraviolet) Oct. 1, 2019. Image courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.

[Link to 48-hour video of the Sun in 193 angstroms]

LOOK at that really cool prominence in the lower right!

Sun in 304 angstroms (extreme ultraviolet) Oct. 1, 2019. Image courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.

Here’s a rotated close-up:

Sunspot Oct. 1 2019 (No AR yet) see in 304 Angstroms. Image courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.

[Link to 48-hour video of the Sun in 304 angstroms]

https://www.facebook.com/photo.php?fbid=10217903910143141&set=gm.2684840711527256&type=3&theater&ifg=1

The solar wind speed is 526.5 km/sec (↑), with a density of 0.3 protons/cm³ (↓) at 1300 UT.

Animated LASCO C2 Coronograph showing the solar corona above the Sun’s limb (the white circle). Credit: NASA/JPL-Caltech

Sun News – Sounding Rocket Payload Looks at the Sun

Upcoming Earth-asteroid encounters:

Notes: LD means “Lunar Distance.” 1 LD = 384,401 km, the distance between Earth and the Moon. Red highlighted entries are asteroids that either pass very close, or very large with high relative velocities to the Earth. Table from SpaceWeather.com

On Sep.24, 2019, the NASA All Sky Fireball Network reported 23 fireballs.
(21 sporadics, 1 southern Taurid)

In this diagram of the inner solar system, all of the fireball orbits intersect at a single point–Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). From: Spaceweather.com

Fireball News

Comet C/2019 Q4

Position of the planets and a couple spacecraft in the inner solar system – the Parker Solar Probe will soon pass orbit of Venus.

Position of the planets and some spacecraft in the inner solar system, Oct. 1 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.

Position of the planets and a couple bodies in the middle solar system:

Position of the planets in the middle solar system, Oct. 1, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.

Position of the planets and a several bodies in the outer solar system:

Position of the planets in the outer solar system, Oct. 1, 2019. Credit: NASA Eyes on the Solar System / Bob Trembley.

Pluto’s Orbit compared to the plane of the ecliptic:

Orbit of Pluto, Oct. 1, 2019 – showing inclination to the plane of the ecliptic. Credit: NASA Eyes on the Solar System / Bob Trembley.

I spent some time in the Pluto system in SpaceEngine generating images for this post. Actually, I spent rather more time there than I thought, but hey, it’s fun to get completely lost in something you love!

Pluto’s moons orbit at a very steep angle compared to the plane of the ecliptic; in 2019 the orbital plane of Pluto’s moons is also nearly flat-on to the plane of the ecliptic – there is no chance of Pluto and Charon eclipsing each other.

Artist’s conception of a the orbital plane of Pluto’s moons in the year 2019 compared to the plane of the ecliptic – rear view. Pluto’s orbit is red, other planet’s orbits are shown in green. Credit: SpaceEngine / Bob Trembley

Pluto and Charon orbit so close to each other that they are tidally-locked with each other; they orbit a common barycenter – which is above the surface of Pluto, so Pluto appears to wobble as Charon orbits around it.

Artist’s conception of a the orbital plane of Pluto’s moons in the year 2019 – side view. The light blue square is the Pluto-Charon barycenter. Credit: SpaceEngine / Bob Trembley

From the surface of Pluto, you will always see the same face of Charon – the same applies to Pluto from the surface of Charon! Each body also appear to hang motionless in the other’s sky, as the stars move slowly in the background.

Artist’s conception of Charon seen from the surface of Pluto. Credit: SpaceEngine / Bob Trembley

Pluto has several smaller moons;