Meteor Activity Outlook for October 20-26, 2018

This fantastic fireball/cloud photograph was captured by Monika L. from near Veszprém, Hungary. It was captured on September 28, 2018 at 18:28 Universal Time. She commented that it was slow and may have produced sounds.

During this period the moon will reach its full phase on Wednesday October 24h. At this time the moon will be located opposite the sun and will lie above the horizon all night long. This weekend the waxing gibbous moon will set during the early morning hours leaving a small window of opportunity to view under dark skies between moonset and the start of morning twilight. The estimated total hourly meteor rates for evening observers this week is near 3 for those viewing from the northern hemisphere and 2 for those located south of the equator. For morning observers the estimated total hourly rates should be near 18 as seen from mid-northern latitudes and 13 from the southern tropics. Rates are reduced during this period due to moonlight. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Note that the hourly rates listed below are estimates as viewed from dark sky sites away from urban light sources. Observers viewing from urban areas will see less activity as only the brighter meteors will be visible from such locations.

The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning October 20/21. These positions do not change greatly day to day so the listed coordinates may be used during this entire period. Most star atlases (available at science stores and planetariums) will provide maps with grid lines of the celestial coordinates so that you may find out exactly where these positions are located in the sky. A planisphere or computer planetarium program is also useful in showing the sky at any time of night on any date of the year. Activity from each radiant is best seen when it is positioned highest in the sky, either due north or south along the meridian, depending on your latitude. It must be remembered that meteor activity is rarely seen at the radiant position. Rather they shoot outwards from the radiant so it is best to center your field of view so that the radiant lies at the edge and not the center. Viewing there will allow you to easily trace the path of each meteor back to the radiant (if it is a shower member) or in another direction if it is a sporadic. Meteor activity is not seen from radiants that are located far below the horizon. The positions below are listed in a west to east manner in order of right ascension (celestial longitude). The positions listed first are located further west therefore are accessible earlier in the night while those listed further down the list rise later in the night.

Radiant Positions at 9pm LST

Radiant Positions at 21:00
Local Daylight Saving Time

Radiant Positions at 01:00 Local Daylight Saving Time

Radiant Positions at 01:00
Local Daylight Saving Time

Radiant Positions at 5am LDT

Radiant Positions at 5:00
Local Daylight Saving Time

These sources of meteoric activity are expected to be active this week..

The Northern Taurids (NTA) are active from a large radiant located at 02:26 (037) +18. This area of the sky is located in central Aries, 5 degrees southeast of the 2nd magnitude star known as Hamal (alpha Arietis). This position is close to the Southern Taurids so care must be taken in separating these meteors. You should have the two radiants near the center of your field of view to properly differentiate these sources. The maximum is not expected until early November so current rates would be 1 per hour or less. These meteors may be seen all night long but the radiant is best placed near 0200 DST when it lies on the meridian and is located highest in the sky. With an entry velocity of 28 km/sec., the average Northern Taurid meteor would be of slow velocity.

The Southern Taurids (STA) are active from a large radiant centered near 02:40 (040) +11. This position lies in southern Aries, 2 degrees northwest of the 4th magnitude star known as mu Ceti. These meteors may be seen all night long but the radiant is best placed near 0200 DST when it lies on the meridian and is located highest in the sky. Rates at this time should be near 2 per hour regardless of your location. With an entry velocity of 27 km/sec., the average Southern Taurid meteor would be of slow velocity.

The omicron Eridanids (OER) were discovered by Japanese observers using video data from SonotoCo in 2007-2008. The activity period ranges from October 16 – November 24 with maximum activity occurring on November 4th. This is a weak shower that usually produces rates less than 1 per hour, even at maximum activity. The radiant is currently located at 02:44 (041) -03, which places it on the Cetus/Eridanus border, 5 degrees south of the 3rd magnitude star known as Menkar (alpha Ceti). This location is close to the source of the Southern Taurids so care must be taken to separate these meteors. Like the STA’s these meteors may be seen all night long but the radiant is best placed near 0200 DST when it lies on the meridian and is located highest in the sky. With an entry velocity of 29 km/sec., the average omicron Eridanid meteor would be of slow velocity.

The chi Taurids (CTA) were discovered by Dr. Peter Brown  during his 7 year survey using the Canadian Meteor Orbit Radar (CMOR). This source is active from October 20 through November 17 with a maximum occurring near November 3rd. Current rates would be less than 1 per hour no matter your location. The radiant is currently located at 03:15 (049) +24, which places it in eastern Aries , 6 degrees west of the famous naked eye open cluster known as the Pleiades. This location is close to the source of the Northern Taurids so care must be taken to separate these meteors. These meteors may be seen all night long but the radiant is best placed near 0300 LDT when it lies on the meridian and is located highest in the sky. With an entry velocity of 41 km/sec., the average chi Taurid meteor would be of medium velocity.

The Orionids (ORI) reach maximum activity on the morning of October 22nd. Unfortunately the full moon will obscure all but the brighter meteors, severely reducing the number of meteors seen. The is radiant located at 06:20 (095) +16, which places it  in northeastern Orion, 3 degrees west of the 2nd magnitude star known as Alhena (gamma Geminorum). This area of the sky rise between 2200 and 2300 and is best placed near 05:00 DST, when it lies highest above the horizon. Rates with moonlight, with the radiant high in the sky, should be near 5 per hour no matter your location. With an entry velocity of 67 km/sec., most activity from this radiant would be of swift speed.

The nu Eridanids (NUE) were co-discovered by Japanese observers using SonotoCo and Juergen Rendtel and Sirko Molau of the IMO. Activity from this long-period stream stretches from August 23 all the way to November 16. A very shallow maximum occurred near September 24. The radiant currently lies at 06:24 (103) +12, which places it in northeastern Monoceros, 2 degrees southeast of the 3rd magnitude star known as Alzirr (xi Geminorum). This area of the sky is best seen during the last dark hour before dawn when the radiant lies highest in a dark sky. Current rates are expected to be less than 1 per hour during this period no matter your location. With an entry velocity of 67 km/sec., the average meteor from this source would be of swift velocity. Some experts feel that these meteors are early members of the Orionid shower, which peaks on October 22.

The epsilon Geminids (EGE) are active from September 30 through October 25 with maximum activity occurring on October 11. The radiant is currently located at 06:29 (105) +28, which places it in north-central Gemini, 4 degrees northeast of the 3rd magnitude star known as Mebsuta (epsilon Geminorum). This area of the sky is best placed in the sky during the last hour before dawn, when it lies highest above the horizon in a dark sky. Current rates should be less than 1 no matter your location. With an entry velocity of 70 km/sec., most activity from this radiant would be of swift speed.

The lambda Ursae Majorids (LUM) are a recent discovery by Željko Andreić and the Croatian Meteor Network team based on studying SonotaCo and CMN observations (SonotaCo 2007-2011, CMN 2007-2010).  This weak shower is active from October 27-29 maximum activity occurring on the 28th. At maximum the radiant is located at 10:24 (156) +49. This position lies in a sparse area of central Ursa Major, between the 2nd magnitude star Merak (Beta Ursae Majoris) and 3rd magnitude Tania Borealis (Lambda Ursa Majoris). This area of the sky is best placed in the sky during the last hour before dawn, when it lies highest above the horizon in a dark sky. Rates at maximum would be less than 1 no matter your location. With an entry velocity of 61 km/sec., most activity from this radiant would be of swift speed.

The Leonis Minorids (LMI) are active from October 12-Nov 5 with maximum activity occurring on October 22nd. This radiant is currently located at 10:36 (159) +37, which places it in northeastern Leo Minor, 2 degrees northeast of the 4th magnitude star known as beta Leonis Minoris. The radiant is best placed just before dawn when it lies highest in a dark sky. This shower is better situated for observers situated in the northern hemisphere where the radiant rises far higher into the sky before the start of morning twilight. Current rates would be less than 1 no matter your location. At 62km/sec., the average Leonis Minorid is swift. From my personal experience this minor shower produces a high proportion of bright meteors.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately 8 sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near 2 per hour. As seen from the tropical southern latitudes (25S), morning rates would be near 6 per hour as seen from rural observing sites and 1 per hour during the evening hours. Locations between these two extremes would see activity between the listed figures. Rates are reduced during this period due to moonlight.

The list below offers the information from above in tabular form. Rates and positions are exact for Saturday night/Sunday morning except where noted in the shower descriptions.

SHOWER DATE OF MAXIMUM ACTIVITY CELESTIAL POSITION ENTRY VELOCITY CULMINATION HOURLY RATE CLASS
RA (RA in Deg.) DEC Km/Sec Local Daylight Saving Time North-South
Northern Taurids (NTA) Nov 02 02:26 (037) +18 28 02:00 1 – <1 II
Southern Taurids (STA) Oct 29 02:40 (040) +11 27 02:00 2 – 2 II
omicron Eridanids (OER) Nov 04 02:44 (041) -03 29 02:00 <1 – <1 IV
chi Taurids (CTA) Nov 03 03:15 (049) +24 41 03:00 <1 – <1 IV
Orionids (ORI) Oct 22 05:51 (088) +16 67 05:00 5 – 4 I
nu Eridanids (NUE) Sep 24 06:24 (096) +10 67 06:00 1 -1 IV
epsilon Geminids (EGE) Oct 11 06:29 (105) +28 70 06:00 <1 – <1 II
lambda Ursae Majorids (LUM) Oct 28 10:24 (156) +49 62 10:00 <1 – <1 IV
Leonis Minorids (LMI) Oct 22 10:36 (159) +37 62 10:00 1 – <1 IV

Source link

Liquid and Flame Science Work amid Japanese, Russian Maintenance

ISS – Expedition 57 Mission patch.

October 18, 2018

Two Expedition 57 astronauts are working to understand what happens to fluids being transported by spacecraft today. Another crew member also worked on combustion science gear as well as Japanese and Russian systems.

Image above: Two Russian spacecraft, the Soyuz MS-09 crew ship (foreground) and the Progress 70 resupply ship, are pictured docked to the International Space Station as the orbital complex orbited nearly 257 miles above Ukraine. Image Credit: NASA.

Fluid physics and combustion research on the International Space Station helps scientists understand how well-known phenomena on Earth behaves in microgravity. For instance, fluids sloshing around inside fuel tanks can impact how a spaceship steers in space. The way flames burn and create soot in space can also create safety issues for crews.

Flight Engineer Serena Auñón-Chancellor and Commander Alexander Gerst of ESA (European Space Agency) explored how fluids affect spacecraft maneuvers today. The duo set up a pair of tiny mobile satellites known as SPHERES for the test inside Japan’s Kibo lab module. The SPHERES Tether Slosh experiment is observing what happens when the satellites tow a liquid-filled tank versus a solid mass body with a Kevlar tether.

International Space Station (ISS). Animation Credit: NASA

Sergey Prokopyev of Roscosmos opened up the Combustion Integrated Rack in the afternoon and replaced manifold bottles that contain gases for flame experiments. The flight engineer also packed items for disposal on a Japanese cargo ship and checked on Russian ventilation and air conditioning systems.

Related links:

Expedition 57: https://www.nasa.gov/mission_pages/station/expeditions/expedition57/index.html

SPHERES: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=303

SPHERES Tether Slosh: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7381

Combustion Integrated Rack: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=317

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.chArchive link

NASA’s Fermi Mission Energizes the Sky With Gamma-ray Constellations

NASA – Fermi Gamma-ray Space Telescope logo.

Oct. 18, 2018

Long ago, sky watchers linked the brightest stars into patterns reflecting animals, heroes, monsters and even scientific instruments into what is now an official collection of 88 constellations. Now scientists with NASA’s Fermi Gamma-ray Space Telescope have devised a set of modern constellations constructed from sources in the gamma-ray sky to celebrate the mission’s 10th year of operations.

To explore Fermi’s Gamma-ray Constellations, visit: https://fermi.gsfc.nasa.gov/science/constellations/

The new constellations include a few characters from modern myths. Among them are the Little Prince, the time-warping TARDIS from “Doctor Who,” Godzilla and his heat ray, the antimatter-powered U.S.S. Enterprise from “Star Trek: The Original Series” and the Hulk, the product of a gamma-ray experiment gone awry.

“Developing these unofficial constellations was a fun way to highlight a decade of Fermi’s accomplishments,” said Julie McEnery, the Fermi project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “One way or another, all of the gamma-ray constellations have a tie-in to Fermi science.”

Animation above: New, unofficial constellations appear in this image of the sky mapped by NASA’s Fermi Gamma-ray Space Telescope. Fermi scientists devised the constellations to highlight the mission’s 10th year of operations. Fermi has mapped about 3,000 gamma-ray sources — 10 times the number known before its launch and comparable to the number of bright stars in the traditional constellations. Animation Credit: NASA.

Since July 2008, Fermi’s Large Area Telescope (LAT) has been scanning the entire sky each day, mapping and measuring sources of gamma rays, the highest-energy light in the universe. The emission may come from pulsars, nova outbursts, the debris of supernova explosions and giant gamma-ray bubbles located in our own galaxy, or supermassive black holes and gamma-ray bursts — the most powerful explosions in the cosmos — in others.

“By 2015, the number of different sources mapped by Fermi’s LAT had expanded to about 3,000 — 10 times the number known before the mission,” said Goddard’s Elizabeth Ferrara, who led the constellation project. “For the first time ever, the number of known gamma-ray sources was comparable to the number of bright stars, so we thought a new set of constellations was a great way to illustrate the point.”   

The 21 gamma-ray constellations include famous landmarks — such as Sweden’s recovered warship, Vasa, the Washington Monument and Mount Fuji in Japan — in countries contributing to Fermi science. Others represent scientific ideas or tools, from Schrödinger’s Cat — both alive and dead, thanks to quantum physics — to Albert Einstein, Radio Telescope and Black Widow Spider, the namesake of a class of pulsars that evaporate their unfortunate companion stars.

Fermi Gamma-ray Space Telescope. Image Credit: NASA

Ferrara and Daniel Kocevski, an astrophysicist now at NASA’s Marshall Space Flight Center in Huntsville, Alabama, developed a web-based interactive to showcase the constellations, with artwork from Aurore Simonnet, an illustrator at Sonoma State University in Rohnert Park, California, and a map of the whole gamma-ray sky from Fermi. Clicking on a constellation turns on its artwork and name, which includes a link to a page with more information. Other controls switch on the visible sky and selected traditional constellations.

“Fermi is still going strong, and we are now preparing a new all-sky LAT catalog,” said Jean Ballet, a Fermi team member at the French Atomic Energy Commission in Saclay. “This will add about 2,000 sources, many varying greatly in brightness, further enriching these constellations and enlivening the high-energy sky!”

NASA’s Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy and with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

To explore Fermi’s Gamma-ray Constellations, visit: https://fermi.gsfc.nasa.gov/science/constellations/

For more about NASA’s Fermi mission, visit: https://www.nasa.gov/fermi

Animation (mentioned), Image (mentioned), Text, Credits: NASA/Rob Garner/Goddard Space Flight Center, by Francis Reddy.

Greetings, Orbiter.chArchive link