In the Sky This Week – June 26, 2018
Mars shines like a bright unblinking cinder in the early morning sky; I'm truly astounded at how bright Mars has been getting - and it's going to continue to brighten until the end of July.
Mars and Saturn in the southwestern sky at 5:30 AM on June 26, 2018. Credit: Stellarium / Bob Trembley.
This nearing Mars opposition and close approach has been bittersweet for astrophotographers, as the planet is experiencing a global dust storm, and surface features are difficult to resolve.
Spirit and Oppy (@MarsRovers) on Twitter:
Mars Storm Watch: The dust storm now circles the planet. No signal yet from Opportunity, but no response is expected until skies begin to clear. We continue to listen daily. https://t.co/VwuuPwEpPA pic.twitter.com/8q7lDoezxs
— Spirit and Oppy (@MarsRovers) June 20, 2018
The Moon will be between Saturn and the bright star Antares on the evening of June 26th.
The Moon and Saturn in the southeastern sky at 9:30 PM on June 26, 2018. Credit: Stellarium / Bob Trembley.
With each passing evening, the bright star Regulus appears a bit lower in the western sky, and is getting closer to Venus. Next week Regulus and Venus will appear very close together!
Venus in the western sky at 9:30 PM, June 26, 2018. Credit: Stellarium / Bob Trembley.
The Moon
The Moon from June 26-July 2, 2018. Visualizations by Ernie Wright
The Moon is a waxing gibbous heading towards full on June 27th, after which it will be a waning gibbous. The full Moon will appear very close to Saturn the evening of June 27th.
The Moon will be very close to Saturn in the southeastern sky at 9:30 PM on June 27, 2018. Credit: Stellarium / Bob Trembley.
Observing Target: M81 and M82
M81 and M82 are galaxies in Ursa Major, and popular observing targets.
Position of galaxy M82 in Ursa Major. Credit: Stellarium / Bob Trembley.
Finding M81 and M82 is relatively easy when star-hopping using the "bowl of the dipper."
Star-hopping to galaxies M81 and M82. Credit: Stellarium / Bob Trembley.
In small telescopes, the galaxies appear very near each other; M81 as an oval smudge, and M82 as a cigar-shaped smudge.
M81 and M82 as they might appear in a small telescope. Credit: Stellarium / Bob Trembley.
Seen with a space telescope, M81 is a beautiful spiral galaxy. M81 has an active galactic nucleus, harboring a 70 million M☉ (Sol) supermassive black hole; the galaxy's large size and high brightness make it a popular target for amateur astronomers.
The sharpest image ever taken of the large "grand design" spiral galaxy M81 is being released today at the American Astronomical Society Meeting in Honolulu, Hawaii.A spiral-shaped system of stars, dust, and gas clouds, the galaxy's arms wind all the way down into the nucleus. Though the galaxy is located 11.6 million light-years away, the Hubble Space Telescope's view is so sharp that it can resolve individual stars, along with open star clusters, globular star clusters, and even glowing regions of fluorescent gas. The Hubble data was taken with the Advanced Camera for Surveys in 2004 through 2006. This colour composite was assembled from images taken in blue, visible, and infrared light. Credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA). Acknowledgment: A. Zezas and J. Huchra (Harvard-Smithsonian Center for Astrophysics)
Space telescope images of M82 might make one wonder what happened to this galaxy? M82 is a starburst galaxy - creating ten times as many stars as our Milky Way galaxy; this starburst activity is likely due to a "recent" close interaction with M81.
This mosaic image of the magnificent starburst galaxy, Messier 82 (M82) is the sharpest wide-angle view ever obtained of M82. It is a galaxy remarkable for its webs of shredded clouds and flame-like plumes of glowing hydrogen blasting out from its central regions where young stars are being born 10 times faster than they are inside in our Milky Way Galaxy. Credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA). Acknowledgment: J. Gallagher (University of Wisconsin), M. Mountain (STScI) and P. Puxley (NSF).
M82 is five times more luminous than the entire Milky Way, and its core region is one hundred times more luminous than the Milky Way's. Imagine what the night sky of a planet in M82 might look like! The core of the galaxy and any nearby star-forming regions would be very bright, and might light up the entire night sky!
Artist concept of a planet in starburst galaxy M82. Credit: Universe Sandbox²/Bob Trembley
The Sun
Small sunspot group AR2715 is decaying, and what little remains will soon rotate out of view. There is a significant coronal hole at the Sun's south pole, and a more diffuse one in the lower latitudes.
SpaceWeather.com says: "NOAA forecasters say there is a 70% chance of G1-class geomagnetic storms on June 27th when a stream of solar wind hits Earth's magnetic field. The gaseous material is flowing from a large, irregular hole in the sun's atmosphere. High latitude sky watchers should be alert for auroras, especially in the southern hemisphere where winter darkness favors visibility." The solar wind speed is 458.4 km/sec, with a density of 11.9 protons/cm3.
There have been a few small prominences over the last couple days - the most significant activity is rotating out of view on the right side of the video 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 MX4 |
2018-Jun-27
|
5.5 LD
|
8
|
15
|
| 2018 LN2 |
2018-Jun-28
|
10.5 LD
|
9.4
|
87
|
| 2018 MH7 |
2018-Jun-28
|
11.4 LD
|
4.4
|
20
|
| 2018 LR3 |
2018-Jun-29
|
6 LD
|
3.8
|
20
|
| 2018 LT6 |
2018-Jul-01
|
11.6 LD
|
12.9
|
126
|
| 2018 LJ1 |
2018-Jul-01
|
13.9 LD
|
2.7
|
18
|
| 2018 MB7 |
2018-Jul-04
|
2.8 LD
|
11.6
|
63
|
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: 124, this year: 882, all time: 18432.
Potentially hazardous asteroids: 1912 (as of June 26, 2018)
Minor Planets discovered: 779,736 (as of June 26, 2018)
International Asteroid Day is June 30th - on the anniversary of the Tunguska Impact in 1908.
Fireballs
On June 25, 2018, the NASA All Sky Fireball Network reported 16 fireballs.
In this diagram of the inner solar system, all of the fireball orbits 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:
Position of the planets in the inner solar system, June 26, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.
Alternate view of the position of the planets in the inner solar system, June 26, 2018. Credit: NASA Eyes on the Solar System / Bob Trembley.
Exoplanets
Confirmed Exoplanets: 3,735 (5/31/2018)
Multi-Planet Systems: 614 (5/31/2018)
Kepler Candidate Exoplanets: 4,496 (8/31/2017)
TESS Candidate Exoplanets: 0
Data from the NASA Exoplanet Archive
Exoplanet of the Week: TrES-4 B
TrES-4 orbits its primary star every 3.543 days and eclipses it when viewed from Earth. The planet is 0.919 times as massive as Jupiter but 1.799 times the diameter, the largest planet ever found at the time (next to WASP-17b, found on 1 May 2009), giving it an average density of only about 0.333 grams per cubic centimetre, approximately the same as Saturn's moon Methone. This made TrES-4 both the largest known planet and the planet with the lowest known density at the time of its discovery.- Wikipedia
Exoplanet TRES-4 B compared with Jupiter. 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.