In the Sky This Week – April 23, 2019

Did you get a chance to see the conjunction of Jupiter and the Moon the the predawn sky this morning? I did as I drove my wife to work.

The Moon was in conjunction with Jupiter high in the southern sky on Apr. 23rd; Saturn and the star Antares appear on either side. Credit: Stellarium / Bob Trembley.

Mercury and Venus appear very low in the eastern sky just before sunrise all week – seeing Mercury may be a challenge.

Mercury and Venus appear very low in the eastern sky just before sunrise at 6:00 AM on Apr. 24th. Credit: Stellarium / Bob Trembley.

There will be a conjunction of the Moon and Saturn in the eastern predawn sky on April 25th; Jupiter and the star Antares continue to appear in the southwest.

The Moon will be in conjunction with Saturn high in the southern sky on Apr. 25th; Jupiter and the star Antares appear to their west. Credit: Stellarium / Bob Trembley.

Mars continues to move away from the Pleiades – which is very close to setting with the dusk; the constellations Orion and Taurus set shortly after sunset. Over the last several months, Earth’s orbit has taken it away from Mars (see solar system images below).

Mars and the constellations Orion and Taurus in the western sky after sunset on Apr. 24th. Credit: Stellarium / Bob Trembley.

M5 – The Rose Cluster

The globular cluster Messier 5, shown here in this NASA/ESA Hubble Space Telescope image, is one of the oldest belonging to the Milky Way. The majority of its stars formed more than 12 billion years ago, but there are some unexpected newcomers on the scene, adding some vitality to this aging population. Stars in globular clusters form in the same stellar nursery and grow old together. The most massive stars age quickly, exhausting their fuel supply in less than a million years, and end their lives in spectacular supernovae explosions. This process should have left the ancient cluster Messier 5 with only old, low-mass stars, which, as they have aged and cooled, have become red giants, while the oldest stars have evolved even further into blue horizontal branch stars. Yet astronomers have spotted many young, blue stars in this cluster, hiding amongst the much more luminous ancient stars. Astronomers think that these laggard youngsters, called blue stragglers, were created either by stellar collisions or by the transfer of mass between binary stars. Such events are easy to imagine in densely populated globular clusters, in which up to a few million stars are tightly packed together. Messier 5 lies at a distance of about 25 000 light-years in the constellation of Serpens (The Snake). This image was taken with Wide Field Channel of Hubble’s Advanced Camera for Surveys. The picture was created from images taken through a blue filter (F435W, coloured blue), a red filter (F625W, coloured green) and a near-infrared filter (F814W, coloured red). The total exposure times per filter were 750 s, 400 s and 567 s, respectively. The field of view is about 2.6 arcminutes across. Credit: ESA/Hubble & NASA

Messier 5 or M5 (also designated NGC 5904) is a globular cluster in the constellation Serpens. Under extremely good conditions, M5 is just visible to the naked eye as a faint “star” near the star 5 Serpentis. Binoculars or small telescopes will identify the object as non-stellar while larger telescopes will show some individual stars, of which the brightest are of apparent magnitude 12.2. The cluster was discovered by Gottfried Kirch in 1702. – Paraphrased from Wikipedia

Location of the M5 – the Rose Cluster. Credit: Stellarium / Bob Trembley.

The Moon is a waning gibbous, rising after sunset, visible high in the sky after midnight, and visible to the southwest after sunrise.

The third quarter Moon occurs on Apr. 25^th, rising around midnight, and visible to the south after sunrise.

After the 25^th, the Moon will be a waning crescent, visible low to the east before sunrise.

The Moon from Apr. 23-29, 2019. Visualizations by Ernie Wright / NASA’s Scientific Visualization Studio.

Moon News – Earth Day (a day late)

The Sun has been spot-free for 2 days. AR2738 has rotated out of view, but you can still see coronal loops associated with it on the Sun’s limb; a coronal mass ejection blew off the Sun from that region in the first second of the videos below.

Coronal holes appear at both poles, and a snake-like coronal hole appear below the equator. SpaceWeather.com says: “A southern hole in the sun’s atmosphere is spewing a stream of solar wind toward Earth. Minor geomagnetic storms are possible when the gaseous material arrives on April 24-25. NASA’s STEREO-A spacecraft has already encountered the solar wind stream and measured its velocity: Between 500 and 600 km/s. Polar auroras may be seen despite waning full moonlight.”

Several long-lived prominences over the last couple days; note the large amount of activity at the start of the video.

The solar wind speed is 338.8 km/sec (↓), with a density of 2.9 protons/cm³ (↑).

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

Sun News

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

Asteroid News

On Apr. 22, 2019, the NASA All Sky Fireball Network reported 16 fireballs.
(11 sporadics, 5 April Lyrids)

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

This is the position of the planets and a couple bodies in the solar system:

OSIRIS-REx – Detailed Survey: Equatorial Stations Phase

JAXA HAYABUSA2 – Descent of the SCI (Small Carry-on Impactor)

ExoMars 2020 – Call from Mars Competition!

Climate – NASA’s Earth Now (Beta) Website

Monitor our planet’s vital signs, such as sea level height, atmospheric carbon dioxide concentration and Antarctic ozone. Trace the movement of water around the globe using the gravity map from NASA’s GRACE satellites. Spot volcanic eruptions and forest fires using the carbon monoxide vital sign. Check out the hottest and coldest locations on Earth with the global surface temperature map.

With the “Latest Events” feature, you can explore geo-located satellite images of recent Earth events, including algal blooms, super storms and wildfires.

Data from the NASA Exoplanet Archive

Exoplanet News

Exoplanet Artwork by Bob Trembley

Hypothetical Dwarf Moon T Ceti 6.D4. Credit: Space Engine / Bob Trembley.

https://twitter.com/__Moon2Mars/status/1118247945818836994

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.
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.
Space Engine: a free 3D Universe Simulator for the PC. VR support coming soon!

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
The Universe – Universe Today

2018 is NASA’s 60th Anniversary!

July 20, 2019 is the 50^th Anniversary of the Apollo 11 landing on the Moon.