A three-planet conjunction of Mars, Jupiter and Saturn continues in the early morning southeastern sky; Mars passes very close to Saturn on March 31st, and by the start of next week will be well beyond Saturn.
Venus is high in the western sky well after sunset; each evening, Venus will move a bit upwards towards the Pleiades star cluster, until it appears to be part of the cluster itself on the evening of April 6th!
Venus appears near the Pleiades star cluster in the western sky after sunset this week. Credit: Stellarium / Bob Trembley.
Venus appears to be part of the Pleiades star cluster in the western sky after sunset on April 3rd. Credit: Stellarium / Bob Trembley.
The Moon is a waxing crescent, visible toward the southwest in early evening.
The first-quarter Moon occurs on April 1st, it will be visible high in the southern sky in early evening.
After April 1st the Moon will be a waxing gibbous, visible to the southeast in early evening, and up for most of the night.
The Moon from 2020-03-31 – 2020-04-06. Visualizations by Ernie Wright / NASA’s Scientific Visualization Studio.Apollo 8 and 13 – Jim Lovell at 92
A small sunspot from solar cycle 25 is emerging on the limb of the Sun – the active region is visible on the upper left side of the videos below.
The northern coronal hole appears diminished; the southern coronal hole remains open and very large!
The Sun seen in 193 angstroms (extreme ultraviolet) Mar. 30, 2020:
Lots of small prominences on the Sun’s limb over the last couple days; as I was writing this I had to laugh because those “small” prominences are larger than the Earth!
The Sun seen in 304 angstroms (extreme ultraviolet) Mar. 30, 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=10221707205210292&set=gm.3087463501264973&type=3&theater&ifg=1
Solar Corona
Solar wind speed is 463.3 km/sec (↑), with a density of 11.2 protons/cm3 (↑) at 0856 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-SOHOSun News
The SunRISE mission will fly six cubesats that will form a virtual radio antenna in Earth orbit to monitor solar activity at wavelengths that can’t be studied from the Earth. Credit: Univ. of MichiganAs I’m writing this, I’m trying to track down an image of these cubesats – the articles I’ve seen discuss the mission, but don’t have photos of the satellites themselves.
Potentially hazardous asteroids: 2018 (last updated Oct. 1, 2019)
Total Minor Planets discovered: 957,596 (+115) I wonder if this number is so much lower than the last couple months because of researchers staying at home?
Upcoming Earth-asteroid encounters:
| Asteroid |
Date(UT)
|
Miss Distance
|
Velocity (km/s)
|
Diameter (m)
|
| 2020 FB4 |
2020-Mar-31
|
12 LD
|
6.2
|
16
|
| 2020 FA1 |
2020-Mar-31
|
18.3 LD
|
2.2
|
18
|
| 2020 FG6 |
2020-Apr-02
|
5.4 LD
|
7.1
|
14
|
| 2019 GM1 |
2020-Apr-02
|
9 LD
|
4.2
|
14
|
| 2020 FK3 |
2020-Apr-03
|
10.4 LD
|
9.7
|
27
|
| 2015 FC35 |
2020-Apr-04
|
10.5 LD
|
13.8
|
148
|
| 2020 FL6 |
2020-Apr-04
|
5.1 LD
|
12.1
|
32
|
| 2020 DT3 |
2020-Apr-05
|
17.6 LD
|
11.8
|
200
|
| 2020 FQ6 |
2020-Apr-06
|
17.9 LD
|
11.2
|
32
|
| 2020 FL4 |
2020-Apr-09
|
10.5 LD
|
4.6
|
16
|
| 2020 FW4 |
2020-Apr-09
|
19.7 LD
|
18.6
|
162
|
| 2019 HM |
2020-Apr-10
|
7.2 LD
|
3.2
|
23
|
| 363599 |
2020-Apr-11
|
19.2 LD
|
24.5
|
224
|
| 2020 FX3 |
2020-Apr-15
|
14.1 LD
|
10.2
|
56
|
| 2019 HS2 |
2020-Apr-26
|
13.6 LD
|
12.6
|
17
|
| 2019 GF1 |
2020-Apr-27
|
18.7 LD
|
3.2
|
12
|
| 2020 FM6 |
2020-Apr-27
|
14.7 LD
|
17
|
147
|
| 52768 |
2020-Apr-29
|
16.4 LD
|
8.7
|
2457
|
| 2020 DM4 |
2020-May-01
|
18.4 LD
|
6.4
|
165
|
| 438908 |
2020-May-07
|
8.9 LD
|
12.8
|
282
|
| 2016 HP6 |
2020-May-07
|
4.3 LD
|
5.7
|
31
|
| 388945 |
2020-May-10
|
7.3 LD
|
8.8
|
295
|
| 2000 KA |
2020-May-12
|
8.9 LD
|
13.5
|
162
|
| 478784 |
2020-May-15
|
8.5 LD
|
3.6
|
28
|
| 136795 |
2020-May-21
|
16.1 LD
|
11.7
|
892
|
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 Mar. 30, 2020, the NASA All Sky Fireball Network reported 3 fireballs.
(3 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 & Meteor News:
https://twitter.com/James_Crabtree/status/1243730951181656065
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, 2020-03-31. Credit: NASA Eyes on the Solar System / Bob Trembley.Position of the planets in the middle solar system.
Position of the planets in the middle solar system, 2020-03-31- the orbit of asteroid 2 Pallas is highlighted. Credit: NASA Eyes on the Solar System / Bob Trembley.2 Pallas was recently imaged using the SEO’s SPHERE instrument:
Image of 2 Pallas from ESO’s Spectro-Polarimetric High-contrast Exoplanet REsearch (VLT-SPHERE). Credit: ESO/Vernazza et al.Position of the planets and interstellar comet C/2019 Q4 (Borisov) in the outer solar system:
Side view of the outer solar system on 2020-03-30 showing the trajectory of interstellar comet C/2019 Q4 (Borisov). Credit: SpaceEngine / Bob Trembley.
OSIRIS-REx Asteroid Sample Return Mission
Hubble Space Telescope
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 the Epsilon Eridani system, 10.5 light years distant.
Distance to Epsilon Eridani from Sol; the plane (green) is aligned with the orientation of the plane of the Milky Way galaxy. Credit: SpaceEngine / Bob Trembley.Epsilon Eridani
Epsilon Eridani (ε Eri, ε Eridani) is a star in the southern constellation Eridanus, just south of the celestial equator. It can be seen from most of Earth’s surface.
It is 10.5 light years (ly) away, and has an apparent magnitude of 3.73. It is the third closest individual star or star system visible to the unaided eye.
Epsilon Eridani was the closest star known to host a planet until the unconfirmed discovery of Alpha Centauri Bb. Its age is less than a billion years. Because of its youth, Epsilon Eridani has a more active magnetic field than the present-day Sun. Its stellar wind is 30 times as strong. Its rotation period is 11.2 days at the equator. The star is smaller and less massive than the Sun, and has a lower level of metal elements. It is a main-sequence star of spectral class K2, which means that energy generated at the core through nuclear fusion of hydrogen is emitted from the surface at a temperature of about 5,000 K, giving it an orange hue.
Its planet, Epsilon Eridani b, was announced in 2000. The planet orbits in about 7 years. It is about 3.4 astronomical units (AU) away from its star.
The system includes two belts of rocky asteroids: one at about 3 AU and a second at about 20 AU, whose structure may be maintained by a hypothetical second planet, Epsilon Eridani c. Epsilon Eridani has an extensive outer debris disk of remnant planetesimals left over from the system’s formation.
Epsilon Eridani may be a member of the Ursa Major Moving Group of stars that share a similar motion through the Milky Way. This suggests they share a common origin in an open star cluster. Its nearest neighbor, the binary star system Luyten 726-8, will have a close encounter with Epsilon Eridani in about 31,500 years when they will be separated by about 0.93 ly.
Epsilon Eridani has been the target of SETI searches. Epsilon Eridani appears in science fiction stories and has been suggested as a destination for interstellar travel. – Wikipedia
Epsilon Eridani system architecture:
Epsilon Eridani System Architecture. Credit: SpaceEngine / Bob Trembley.Orbit of exoplanet Epsilon Eridani b:
Orbit of exoplanet Epsilon Eridani b. Credit: SpaceEngine / Bob Trembley.Artist’s concept of exoplanet Epsilon Eridani b:
Artist’s concept of exoplanet Epsilon Eridani b. Credit: SpaceEngine / Bob TrembleyStay 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.
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. NOTE: Version v0.20.0 was released!
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.
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
