Saturn and Jupiter, continuing their months-long conjunction, appear in the southern predawn sky all week.
The ongoing conjunction of Saturn and Jupiter appears in the southern predawn sky this week. Credit: Stellarium / Bob Trembley.Mars appears in the southeastern sky all week; the waning crescent Moon appears in the eastern predawn sky from June 16-19th.
A waning crescent Moon appears in the eastern predawn on June 16th; Mars appears in the southeastern predawn sky this week. Credit: Stellarium / Bob Trembley.A very thin waning crescent moon appears near the planet Venus in the east-northeastern predawn sky on June 19th; with a good likelihood of earthshine on the Moon, this will be an excellent opportunity to take some astrophotos!
A very thin waning crescent moon appears very close to Venus in the east-northeastern predawn sky on June 19th. Credit: Stellarium / Bob Trembley.The constellation Hercules and the globular cluster M13 appear nearly overhead at midnight this week.
The constellation Hercules and the globular cluster M13 appear nearly overhead at midnight this week. Credit: Stellarium / Bob Trembley.
M13 Wide-Field image. Credit: Creative Commons CC BY-SA 3.0
The Moon is a waning gibbous – visible low to the east before sunrise.
The new Moon occurs on June 21st.
After June 21st the Moon will be a waxing crescent – visible toward the southwest in early evening.
The Moon from 2020-06-16 – 2020-06-22. Visualizations by Ernie Wright / NASA’s Scientific Visualization Studio.Moon Humor
Sunspot AR2765 from last week is decaying and rotating around the Sun’s western limb. Large coronal holes remain open at both poles.
The Sun seen in 193 angstroms (extreme ultraviolet) June 15, 2020:
Moderate prominence activity on the Sun’s limb over the last few days.
The Sun seen in 304 angstroms (extreme ultraviolet) June 15, 2020:
You can view the Sun in near real-time, in multiple frequencies here: SDO-The Sun Now.
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.
Facebook: SolarActivity
https://www.facebook.com/photo.php?fbid=10158119954238758&set=a.84074588757&type=3&theater&ifg=1
Solar Corona
Solar wind speed is 453.5 km/sec (↑), with a density of 1.1 protons/cm3 (↓) at 2346 UT.
Near real-time animation of the corona and solar wind from the Solar & Heliospheric Observatory (SOHO):
Animated LASCO C2 Coronograph showing the solar corona above the Sun’s limb (the white circle). Credit: NASA/JPL-Caltech-SOHO
Potentially hazardous asteroids: 2037 (last updated June 2, 2020)
Total Minor Planets discovered: 958,714 (+52)
Upcoming Earth-asteroid encounters:
| Asteroid |
Date(UT)
|
Miss Distance
|
Velocity (km/s)
|
Diameter (m)
|
| 2020 KP6 |
2020-Jun-16
|
3.6 LD
|
10.8
|
41
|
| 2020 JU3 |
2020-Jun-17
|
6.9 LD
|
10.9
|
55
|
| 2020 KF3 |
2020-Jun-17
|
12.5 LD
|
3.4
|
15
|
| 2020 LG |
2020-Jun-18
|
8.9 LD
|
10.6
|
51
|
| 2018 PD22 |
2020-Jun-19
|
17.2 LD
|
14.6
|
56
|
| 2020 KR1 |
2020-Jun-22
|
11.6 LD
|
6.8
|
42
|
| 441987 |
2020-Jun-24
|
9.8 LD
|
12.9
|
186
|
| 2017 FW128 |
2020-Jun-25
|
6.9 LD
|
5.4
|
11
|
| 2020 KQ7 |
2020-Jun-27
|
10.3 LD
|
2.6
|
18
|
| 2020 JX1 |
2020-Jun-29
|
3.3 LD
|
5
|
60
|
| 2019 AC3 |
2020-Jul-01
|
10.5 LD
|
3.4
|
12
|
| 2007 UN12 |
2020-Jul-04
|
16.7 LD
|
2.9
|
6
|
| 2020 LS |
2020-Jul-04
|
19.4 LD
|
11.5
|
73
|
| 2020 KJ7 |
2020-Jul-13
|
11.9 LD
|
3.4
|
30
|
| 2009 OS5 |
2020-Jul-13
|
17.6 LD
|
2.6
|
45
|
| 2016 DY30 |
2020-Jul-19
|
9 LD
|
15.1
|
3
|
| 2002 BF25 |
2020-Jul-21
|
9.4 LD
|
6.8
|
129
|
| 2018 PY7 |
2020-Jul-31
|
8.9 LD
|
9.5
|
16
|
| 2007 RF1 |
2020-Jul-31
|
10.7 LD
|
5
|
21
|
| 2018 BD |
2020-Aug-03
|
7.6 LD
|
9.4
|
3
|
| 2009 PQ1 |
2020-Aug-05
|
10.8 LD
|
13.5
|
112
|
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
Asteroid News – New Minor Planet Circular with Named Asteroids
Congrats Christopher J. Corbally S.J. on your newly named asteroid! This listing is SO NEW it still appears as 2010 RS10 in the JPL Small Body Database Browser.
(119248) Corbally = 2001 RS10
Discovered 2001 Sept. 10 by R. A. Tucker at at the Goodricke-Pigott Observatory, Tucson.
Christopher J. Corbally S.J. (b. 1946) was ordained in the Society of Jesus and earned a PhD in astronomy. He continues a long career in astronomy where his contributions have included areas of multiple stellar systems, stellar spectral classification, galactic structure, star formation and telescope technology.
A member of NASA’s OSIRIS-REx asteroid sample return mission got a named asteroid:
(133832) Loveridge = 2003 XJ39
Discovered 2003 Dec. 5 by the Catalina Sky Survey.
Michael Francis Ubaldo Loveridge (b. 1993) worked on NASA’s OSIRIS-REx Mission as a software engineer at the Science Processing and Operations Center.
His primary contributions included work on science data assembly and processing software.
Another named asteroid that caught my eye was:
(503033) New Hampshire = 2015 FE144
Discovered∗ 2005 Mar. 3 by the Catalina Sky Survey.
New Hampshire is a state located in the northeast corner United States, within the region of New England. The capitol is the city of Concord. It is nicknamed The
Granite State due to its high supply of quality granite. The state motto, Live Free or Die, accurately captures the strongly held sentiment of its citizens.
Link to MPC Circular: https://minorplanetcenter.net/iau/ECS/MPCArchive/2020/MPC_20200603.pdf
On June 8, 2020, the NASA All Sky Fireball Network reported 9 fireballs.
(9 sporadics)
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). Credit: SpaceWeather.comFireball News – HUGE Green Fireball Over Australia
Position of the planets and a couple spacecraft in the inner solar system:
Position of the planets and a couple spacecraft in the inner solar system, 2020-06-16. Credit: NASA Eyes on the Solar System / Bob Trembley.Position of the planets in the middle solar system – the orbit of asteroid 216 Kleopatra is highlighted.
Position of the planets in the middle solar system, 2020-06-16 – the orbit of asteroid 216 Kleopatra is highlighted. Credit: NASA Eyes on the Solar System / Bob Trembley.Asteroid 216 Kleopatra
Artistic rendering of Asteroid 216 Kleopatra from radar imaging data. Credit: NASA Eyes on the Solar System / Bob Trembley.216 Kleopatra is a metallic, ham-bone-shaped asteroid and trinary system orbiting in the central region of the asteroid belt, approximately 138 kilometers (86 miles) in diameter. It was discovered on 10 April 1880, by Austrian astronomer Johann Palisa at the Austrian Naval Pola Observatory, in what is now Pula, Croatia. The M-type asteroid has a shorter than average rotation period of 5.4 hours. It was named after Cleopatra, the famous Egyptian queen. Two small minor-planet moons were discovered in 2008, and later named Alexhelios and Cleoselene.
Kleopatra is a relatively large asteroid, measuring 217 × 94 × 81 km. Calculations from its radar albedo and the orbits of its moons show it to be a rubble pile, a loose amalgam of metal, rock, and 30–50% empty space by volume, likely due to a disruptive impact prior to the impact that created its moons.
Kleopatra has an unusual shape. Initial observations with the ESO 3.6 m Telescope at La Silla, run by the European Southern Observatory, were interpreted to show a double source with two distinct lobes of similar size. These results were disputed when radar observations at the Arecibo Observatory showed that the two lobes of the asteroid are connected, resembling the shape of a ham-bone. The radar observations provided a detailed shape model that appeared on the cover of Science Magazine. – Wikipedia
Position of the planets some transneptunian objects in the outer solar system:
Position of the planets in the middle solar system, 2020-06-16 – the orbit of dwarf planet and transneptunian object Eris is highlighted. Credit: NASA Eyes on the Solar System / Bob Trembley.Highlight: Planet Venus
Venus dayside synthesized false color image by UVI (2018 Mar 18). Credit: JAXA.Venus is the second planet from the Sun. It is named after the Roman goddess of love and beauty. As the second-brightest natural object in the night sky after the Moon, Venus can cast shadows and can be, on rare occasion, visible to the naked eye in broad daylight. Venus lies within Earth’s orbit, and so never appears to venture far from the Sun, either setting in the west just after dusk or rising in the east a bit before dawn. Venus orbits the Sun every 224.7 Earth days. With a rotation period of 243 Earth days, it takes longer to rotate about its axis than any other planet in the Solar System and does so in the opposite direction to all but Uranus (meaning the Sun rises in the west and sets in the east). Venus does not have any moons, a distinction it shares only with Mercury among planets in the Solar System.
Venus is a terrestrial planet and is sometimes called Earth’s “sister planet” because of their similar size, mass, proximity to the Sun, and bulk composition. It is radically different from Earth in other respects. It has the densest atmosphere of the four terrestrial planets, consisting of more than 96% carbon dioxide. The atmospheric pressure at the planet’s surface is 92 times that of Earth, or roughly the pressure found 900 m (3,000 ft) underwater on Earth. Venus is by far the hottest planet in the Solar System, with a mean surface temperature of 735 K (462 °C; 863 °F), even though Mercury is closer to the Sun. Venus is shrouded by an opaque layer of highly reflective clouds of sulfuric acid, preventing its surface from being seen from space in visible light. It may have had water oceans in the past, but these would have vaporized as the temperature rose due to a runaway greenhouse effect. The water has probably photodissociated, and the free hydrogen has been swept into interplanetary space by the solar wind because of the lack of a planetary magnetic field. Venus’s surface is a dry desertscape interspersed with slab-like rocks and is periodically resurfaced by volcanism.
As one of the brightest objects in the sky, Venus has been a major fixture in human culture for as long as records have existed. It has been made sacred to gods of many cultures, and has been a prime inspiration for writers and poets as the morning star and evening star. Venus was the first planet to have its motions plotted across the sky, as early as the second millennium BC.
In January 2020, astronomers reported evidence that suggests that Venus is currently volcanically active.- Wikipedia
SpaceEngine on Steam has some free downloadable content (DLC) featuring high resolution radar images of Venus’ surface from NASA’s Magellan mission.
Surface features of Venus – radar imaged by NASA’s Magellan mission. Credit: SpaceEngine / Bob Trembley.Read more about Venus on NASA’s Solar System Exploration site: https://solarsystem.nasa.gov/planets/venus/overview/
OSIRIS-REx Asteroid Sample Return Mission
International Space Station
NASA Perseverance Mars Rover
Hubble Space Telescope
ESA Solar Orbiter
Climate
ex·o·plan·et /ˈeksōˌplanət/, noun: a planet orbiting a star other than the Sun.
Data from the NASA Exoplanet Archive
* Confirmed Planets Discovered by TESS refers to the number planets that have been published in the refereed astronomical literature.
* TESS Project Candidates refers to the total number of transit-like events that appear to be astrophysical in origin, including false positives as identified by the TESS Project.
* TESS Project Candidates Yet To Be Confirmed refers to the number of TESS Project Candidates that have not yet been dispositioned as a Confirmed Planet or False Positive.
The Local Stellar Neighborhood
Continuing with my visual tour of nearby stars and their systems, we travel to Tau Ceti, about 11.7 light years distant.
Distance to Tau Ceti from Sol; the plane (green) is aligned with the orientation of the plane of the Milky Way galaxy. Credit: SpaceEngine / Bob Trembley.Tau Ceti
Tau Ceti (τ Cet, τ Ceti) is a star in the constellation Cetus. It can be seen with the unaided eye as a third-magnitude star.
It has a spectrum similar to the Sun, but is only 78% of the Sun’s mass. It is just under 12 light-years from the Solar System, a relatively nearby star. It is the closest solitary G-class star. The star appears stable, and is “metal-deficient” because (like the Sun) it is mostly made of hydrogen and helium.
There is more than ten times as much dust surrounding Tau Ceti as in the Solar System. There are probably five planets orbiting Tau Ceti, two in the habitable zone. Because of its debris disk, any planet orbiting Tau Ceti would get far more impact events than Earth. Despite this, its Sun-like characteristics have led to widespread interest in the star. Tau Ceti is consistently listed as a target for the Search for Extra-Terrestrial Intelligence (SETI), and it appears in some science fiction literature.
On December 19, 2012, evidence was presented for a system of five planets orbiting Tau Ceti. The planets’ estimated minimum masses are between two and six times the Earth’s mass. Their orbital periods range from 14 to 640 days. One of them, Tau Ceti e, appears to orbit about half as far from Tau Ceti as Earth does from the Sun. With Tau Ceti’s luminosity of 52% that of the Sun and a distance from the star of 0.552 AU, the planet would receive 1.71 times as much stellar radiation as Earth does. This is slightly less than Venus, which gets 1.91 times Earth’s. Some research places it within the star’s habitable zone.
The habitable zone for a star is where liquid water could be present on an Earth-like planet. For Tau Ceti, this is at a radius of 0.55–1.16 AU, where 1 AU is the average distance from the Earth to the Sun. – Wikipedia
NOTE: The Wikipedia article says 5 exoplanets, but at the time of this writing, NASA’s exoplanet archive only shows 4 for Tau Ceti; SpaceEngine also shows only 4 exoplanets.
Tau Ceti System Architecture
Tau Ceti Exoplanet Orbital Diagram
Top-down view of the exoplanet orbits around the star Tau Ceti – the orbit of Tau Ceti f is highlighted in red . Credit: SpaceEngine / Bob Trembley.Artist’s Rendering of Exoplanet Tau Ceti f
Artistic rendering of exoplanet Tau Ceti f. Credit: SpaceEngine / Bob Trembley.Stay safe, be well, and look up!
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.
Universe Sandbox: a space simulator that merges real-time gravity, climate, collision, and material interactions to reveal the beauty of our universe and the fragility of our planet. Includes VR support.
SpaceEngine: a free 3D Universe Simulator for Windows. Steam version with VR support available.
Stellarium: a free open source planetarium app for PC/MAC/Linux. It’s a great tool for planning observing sessions. A web-based version of Stellarium is also available.
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
Light Pollution – NASA’s Black Marble
The Universe – Universe Today
