Crashing harder than Schiaparelli. In the show this time, we talk to Dr. Laura Spitler repeating fast radio burst, Ian Evans rounds up the latest news, and we find out what we can see in the November night sky from Ian Morison and Claire Bretherton.
In the news this month: The Schiaparelli Lander, The Lyman Alpha Blob, and More galaxies than we thought.
In the October edition of the Jodcast we discussed the upcoming Schiaparelli Lander component of the joint European/Russian mission to Mars, the ExoMars Trace Gas Orbiter mission. It was anticipated with some trepidation. Mankind's record for landing successfully on the surface of Mars has not been good. Of the forty four missions recorded by NASA, only twenty are considered to be successful or partially successful. The roll call of failures include the Mars Polar Orbiter and Beagle Two which was a partial success as even though the lander failed, the Mars Orbiter Express sent much useful data. Sadly the ExoMars mission will also have to be classified as partially successful. While the orbiter was successfully placed in a high altitude holding orbit around Mars, the lander impacted at high speed on the surface.
Getting to the surface is tougher than on Earth as the atmosphere is one hundred times thinner. Typically space probes use aerobraking to slow themselves down. Friction from the atmosphere converts kinetic energy into heat energy. This isn't as effective in the Martian atmosphere compared to Earth's and means that the lander was travelling at supersonic speeds when the parachute deployed. Previous Mars landers have used a mixture of heat shields, parachutes, retro-rockets and air bags to get themselves safely to the surface.
The Schiaparelli lander was designed as a technology testbed for later European Space Agency missions to the Red Planet. In addition to the supersonic parachute system, it made use of a guidance and control system based on a Doppler radar altimeter sensor, and on-board inertial measurement units. ESA scientists were as interested in the data produced in the descent as they were in whether or not the lander arrived successfully on the surface.
The early phases of the decent proceeded according to plan. Aerobraking slowed the lander from twenty one thousand kilometres an hour down to one thousand seven hundred kilometres an hour. At this point the parachute successfully deployed. Five minutes and twenty two seconds after initial entry to the Martian atmosphere, at an altitude of one point seven kilometres above the surface, the parachute along with the rear cover was to be jettisoned from the lander. At this point thrusters should have fired for thirty seconds bringing the landers speed to 4 kilometres an hour, two metres above Mars. The lander would then drop down to the surface where a carbon fibre cushion would absorb the low speed impact.
Data from the lander suggests that the thruster phase did not go according to plan. Instead of firing for thirty seconds the thrusters fired for just three to four seconds. After this the lander dropped down to the Martian surface in freefall and impacted at a speed of around three hundred kilometres an hour.
Images from the Mars Reconnaissance Orbiter of the landing site showed two new features. One believed to be the parachute and rear cover, the other the impact site of the lander about one kilometre north of the parachute. It is believed that the fuel for the fuel tanks for the thrusters exploded on impact completely destroying the lander. The impact site was only four point five kilometres from the intended landing site and was well within the nominal landing ellipse.
Any fall from a great height can be considered to be successful until the impact. This can actually be said for the Schiaparelli lander which sent back six hundred megabytes of data on the decent up to the impact. This data will be used in later missions including the ExoMars rover, due to be launched in Twenty twenty.
On a positive note, the ExoMars Trace Gas Orbiter will be placed into a circular orbit two hundred and fifty miles above Mars after calibration tests in November. It will then be searching for gases such as methane, to establish whether the gas is produced in the atmosphere as a result of geological or biological activity. If the methane is accompanied by propane or ethane this may be a marker that indicates that it originates from a biological source. If it is seen with Sulphur Dioxide then it is more likely to originate from geological activity. In addition the ExoMars Trace Gas Orbiter will act as a communications relay for future ESA missions to Mars through to the year Twenty twenty two.
Jodcast listeners who are of a certain age or movie buffs will recall Steve McQueen's first starring role in a wonderful film called "The Blob". In this 1950s drive in-movie staple, a blob looking suspiciously like unset strawberry jelly invades from outer space the small US town of Downingtown, Pennsylvania and proceeds to engulf and devour its unfortunate inhabitants. The end credit of the film is simply "The End" with a question mark. Suggesting that maybe the story wasn't over and maybe there would be more incidents involving the blob. That question mark can now be answered. It was the end of the film and there is no such thing as a blob which will invade from outer space and devour any of us.
However I know that all of us at Jodcast central felt a strange frisson of fear when hearing of scientists attempts to understand the origins of giant blobs in outer space.
An international team headed by Jim Geach, from the centre of Astrophysics research of the University of Hertfordshire have used data from the Atacama Large Millimeter Array (ALMA) alongside data from the Multi Unit Spectroscopic Explorer instrument mounted on the Very Large Telescope in Northern Chile to gain an understanding of Lyman Alpha Blob One, one of thirty Lyman Alpha blobs discovered since the year two thousand.
The SSA22 Lyman Alpha Blob One is one of the largest structures in the universe being four hundred thousand light years in diameter. It is eleven point five billion light years away so we are seeing it at an early stage in the life of the universe. The radiation from the blob is originally from the ultraviolet part of the spectrum but this is cosmologically red shifted to the visible part of the spectrum.
It is surprising that an object made of diffuse clouds of hydrogen should be so bright that they are visible at such large distances. The team have been trying to understand the mechanisms that lead to the emission of such large amounts of energy. Any Astrophysicist worth their salt when faced with huge amounts of energy will normally say "super massive black holes" and in this case they would be right and wrong. Early X-ray observations of LAB-1 did show a super massive black hole at the centre of a large active galaxy which is embedded in a bubble of hydrogen gas. Observations from ALMA have since shown at least two large galaxies surrounded by smaller galaxies. At some point in their future and our past these galaxies will combine to form a giant elliptical galaxy.
All of these are regions of extraordinary star formation. Over one hundred times as many stars are being formed in these regions compared to the Milky Way. Computer models lead the team to the suggestion that the radiation from these young hot stars which is principally in the ultraviolet region is scattered by the hydrogen in the clouds surrounding the galaxies. The radiation from these clouds is polarised and the team used this finding to confirm the prediction made by the model.
When we look at LAB one, we are looking at the building blocks of the formation of a massive elliptical galaxy. Galaxy formation has been an issue for cosmologists for many years and this provides another piece in the jigsaw puzzle.
Sadly, Jim Geach's team has not been able to confirm or deny that the cloud tastes or smells of strawberry.
In December 1995 the Hubble space Telescope spent ten days taking a picture of a small portion of space in the Ursa Major constellation. The Hubble Deep field image covered a tiny part of the night sky, just 2.6 arcminutes on each side. It revealed around three thousand galaxies. When combined with the Ultra Deep Field Astronomers were able to conclude that the number of galaxies in the observable universe is huge, over two hundred billion galaxies.
Christopher Conslice and his team at the University of Nottingham have applied new techniques to those images to report that there are ten times more galaxies than originally thought.
One of the new techniques was to build a three dimensional model of the universe from the original images. They then applied computers models to the galaxies at different distances to infer the presence of other smaller, fainter galaxies. From this they arrived at the estimated two trillion galaxies.
This has gone some way towards solving a problem raised by the original deep field research. The projected two billion galaxies from the initial research were not enough to account for the predicted mass of the universe. Two trillion is a step in the direction expected by theorist but there is still a discrepancy that the team are investigating.
The deep field images show galaxies thirteen billion light years away. This displays the galaxies as they were thirteen billion years ago. Since that time these small faint galaxies will have merged to form the universe with fewer galaxies that we can see in our immediate surroundings.
Astrophysicists are now waiting for the launch and deployment of Hubble's follow-up, the James Webb telescope. This instrument should be able to see even further back to the beginning of the universe to a time when these galaxies were being formed.
Interview with Dr. Laura Spitler
Dr. Laura Spitler is a researcher at the Max Planck Institute for Radio Astronomy in Bonn, Germany, who specialises in the study of radio transients- time variable sources in the radio sky. She talks to us today about a discovery which represents a significant step in our understanding of a particular class of radio transients known as Fast Radio Bursts (FRBs) which have the potential to shed light on the matter distribution in the universe. After discovering an FRB in 2012 using the Aricebo telescope in Puerto Rico, Dr. Spitler has been tirelessly probing the area in which it was found, and in early 2016 reported multiple reocurrences of the original outburst. In this interview Dr. Spitler tells us about why FRBs are exciting many in the transient astronomy research community, explains how a repeating burst may shed light on the origins of these short but powerful sources of emission, and may even answer a listener question or two!
The Night Sky
Ian Morison tells us what we can see in the northern hemisphere night sky during November 2016.
- Jupiter is the only planet that can be seen in the pre-dawn sky this month rising some two and a half hours before the Sun at the start of November, but by around 2:20 UT (GMT) by the end of the month. On the first of November it will lie some 20 degrees above the south-eastern horizon an hour before sunrise and some 10 degrees higher by month's end. Though at its smallest and dimmest, it still has a magnitude of around -1.7 and shows a 32 arc second disk. It remains in Virgo throughout the month and initially lies just 2 degrees below Porrima, Gamma Virginis, and sinks slowly southwards until by month's end it lies half way between Porrima and Spica, Alpha Virginis. With a small telescope, early risers should be able to see the equatorial bands in the atmosphere and the four Gallilean moons as they weave their way around it.
- Saturn is still visible low in the southwest after sunset, but is only some 10 degrees above the horizon 45 minutes after sunset. However as the month progresses it will sink lower and become harder to see. It lies in the southern part of Ophiuchus some 7 degrees up and to the left of Antares in Scorpius. One could not hope for a sharp view (but I am going to try using an Atmospheric Dispersion Corrector to help) but its wide open ring system should be seen. Sadly Saturn is moving towards the southern part of the ecliptic so for quite a few years will only be seen at low elevations
- Mercury, shining at magnitude -0.5 and with a disk some 5 arcs seconds across becomes visible low in the southwest after sunset by the third week of November and slowly climbs higher in the sky until it reaches its furthest angular distance from the Sun in mid December. It might just be spotted close to Venus on the 23rd.
- Mars, moving quickly eastwards through eastern Sagittarius and Capricornus, dims from magnitude +0.4 to +0.6 during November. The red (actually salmon pink) planet can be seen low above the southern horizon throughout the month but, with a disk only about 7 arc seconds across, no surface features will be seen.
- Venus, in the west, sets some 2 hours after the Sun at the start of the month but an hour later by month's end as it begins to dominate the evening sky. Its brightness increases from -4.0 to -4.2 magnitudes during the month whilst the angular size of its gibbous disk increases from 14 to 17 arc seconds. As it does so its phase reduces from 78 to 70% which explains why the brightness changes so little. Venus is moving eastwards, leaving Ophiuchus on the 9th into Sagittarius where it passes over the Teapot and will be just 7.5 arc minutes below its 'lid' star, Lamda Sagittari (shining at magnitude 2.8) on the 17th.
- November early mornings: November Meteors.
In the hours before dawn, November gives us a chance to observe meteors from two showers. The first that it is thought might produce some bright events is the Northern Taurids shower which has a broad peak of around 10 days but normally gives relatively few meteors per hour. The peak is around the 10th of November and, pleasingly, the Moon is first quarter on the 7th so, in the first week of November will have set by midnight. The meteors arise from comet 2P/Encke. Its tail is especially rich in large particles and, this year, we may pass through a relatively rich band so it is possible that a number of fireballs might be observed!
The better known November shower is the Leonids which peak on the night of the 17th/18th of the month. Sadly, the Moon will be just after full so will hinder our view. As one might expect, the shower's radiant lies within the sickle of Leo and meteors could be spotted from the 15th to the 20th of the month. The Leonids enter the atmosphere at ~71 km/sec and this makes them somewhat challenging to photograph but its worth trying as one might just capture a bright fireball. Up to 15 meteors an hour could be observed if near the zenith. The Leonids are famous because every 33 years a meteor storm might be observed when the parent comet, 55P/Temple-Tuttle passes close to the Sun. In 1999, 3,000 meteors were observed per hour but we are now halfway between these impressive events hence with a far lower expected rate.
- Around the beginning and end of November (with no Moon in the sky): find M31 - The Andromeda Galaxy - and perhaps M33 in Triangulum
In the evening, the galaxy M31 in Andromeda is visible in the south. The chart provides two ways of finding it:
1) Find the square of Pegasus. Start at the top left star of the square - Alpha Andromedae - and move two stars to the left and up a bit. Then turn 90 degrees to the right, move up to one reasonably bright star and continue a similar distance in the same direction. You should easily spot M31 with binoculars and, if there is a dark sky, you can even see it with your unaided eye. The photons that are falling on your retina left Andromeda well over two million years ago!
2) You can also find M31 by following the "arrow" made by the three rightmost bright stars of Cassiopeia down to the lower right as shown on the chart.
Around new Moon (11th November) - and away from towns and cities - you may also be able to spot M33, the third largest galaxy after M31 and our own galaxy in our Local Group of galaxies. It is a face on spiral and its surface brightness is pretty low so a dark, transparent sky will be needed to spot it using binoculars (8x40 or, preferably, 10x50). Follow the two stars back from M31 and continue in the same direction sweeping slowly as you go. It looks like a piece of tissue paper stuck on the sky just a bit brighter than the sky background. Good Hunting!
- November 2nd - after sunset: Venus, Saturn and a thin crescent Moon
After sunset on the 2nd and seen in the west, a thin crescent Moon will lie above Saturn (magnitude +0.5) whilst over to the lower left will lie Venus (magnitude -4).
- November 5th - before sunrise: Jupiter lies below Porrima in Virgo
Around one hour before sunrise looking towards the the East-Southeast, Jupiter will be seen lying in Virgo below Porrima, Gamma Virginis, and above Spica, Alpha Virginis.
- November 15th - late evening until sunrise: The full Moon close to the Hyades Cluster.
During the night, the full moon will be seen moving away to the left of the Hyades Cluster in Taurus. Lying half way towards the cluster is the red-giant star Aldebaran.
- November 25th - one hour before sunrise: The third quarter Moon close to Regulus in Leo.
In the hours befor dawn, the third quarter Moon will seen lie close (just over 3 degrees) to Regulus in Leo.
Claire Bretherton from the Space Place at Carter Observatory in New Zealand speaks about the southern hemisphere night sky during November 2016.
Kia ora, and welcome to the November Jodcast from Carter Observatory in Wellington, New Zealand.
As Scorpius/ Te Matau a Maui sets in the west, his arch enemy, and our summer constellation, Orion rises towards the east along with Taurus and Canis Major. The bright star Antares, which marks the heart of the Scorpion, is also known as Rehua to Maori. It represents one of the four Pou, or pillars, that hold Ranginui, the sky father up in the sky. It sits just above the south western horizon at around 11pm at the beginning of the month. These four pou form the basis of a celestial compass, a map of the night sky that was used to navigate the vast oceans of our planet and bring our ancestors to Aotearoa/ New Zealand.
The other three pou are marked by Matariki (the Pleiades), Tautoru (the belt of Orion) and Takurua (Sirius), which line up along the eastern horizon. Matariki supports one of Rangi's shoulders and marks the rising point of the Sun at the winter solstice. Takurua (Sirius) supports the other shoulder and is the closest bright star to the Sun's rising point at the summer solstice. These two stars represent the extent of the Sun's movement throughout the year. In between, rising directly east, is Tautoru, or the belt of Orion, marking the rising point of the Sun at the time of the equinox.
Stretching from Scorpius around to Orion is Te Waka o Tamareriti, or Tamarereti's canoe, which lines up along the horizon in our evening sky. The front of the canoe is marked by the tail of Scorpius, with the sting representing the beautifully carved wood that adorns the prow. The star at the end of the Scorpion's curving tail marks the place where the bow meets the water, whilst the bright, orange star, Antares, marks the crest of a wave as the great waka glides through the waters of the Milky Way.
The Southern cross marks the anchor, Te Punga and the pointers, alpha and Beta Centauri are the anchor line, Te Taura. The key seasonal markers of Takurua (Sirius) and Rehua (Antares) are on either side.
Orion marks the stern of the canoe, with the elaborately carved stern post rising all the way up from red Betelgeuse to bluish Rigel. A tall mast rises from the waka all the way to Achernar, high in the south, which, at magnitude 0.46, is the brightest start in the southern constellation of Eridanus, the river, and the tenth brightest in the night sky.
A little below Achernar are two small fuzzy patches of light, the Large and Small Magellanic Clouds, which mark the waka's sails.
One story tells of Tamarereti sailing across the sky in his waka with all the stars in kete or baskets. He places the key seasonal and navigational stars in their correct positions in the sky, but finds he has lots of smaller stars left over. So he capsizes his waka spilling all the smaller stars into the sky forming Te Ika Roa, or the Milky Way. Another story tells of Tamareriti scattering bright pebbles in the dark, lightless sky to help guide his way home. The pebbles became the stars and the wake of his waka formed the Milky Way.
The sky we see in the mid-evening in October/November each year is, in fact, the same sky we see just before sunrise around June, the time we celebrate Matariki, or Māori New Year. It is said that the bright star Canopus, or Atutahi (the ariki or high chief of the heavens), pulls up the anchor at the start of the year starting the waka in motion. During the year you can track the progress of Tamarereti's waka as it moves across the sky, one day at a time.
Canopus is the second brightest star in the night time sky, with a magnitude of -0.74, and the brightest in the southern constellation of Carina. It is a white F-type supergiant with a mass around 10 times that of our Sun. It can be seen midway up the south eastern evening sky this month.
Saturn can still be found in our evening skies at the start of the month, just to the right of Antares, and setting around 9:30, but it will disappear into the evening twilight by months end. Venus starts November just above the pair, but continues to move eastwards against the background stars, rising through Sagittarius over the second half of the month. On the 17th, you'll find it right at the tip of the lid of the upside down teapot asterism. Venus will be setting around 3 hours and 20 minutes after the Sun throughout November.
Mars is higher still, and continues to hold its position well, moving from Sagittarius through Capricorn, and setting after midnight.
Mercury also makes an appearance this month. On the 20th it moves between Saturn and Antares forming a line of similar brightness "stars" along the dusk horizon, before continuing to move up away from the pair. Unfortunately, Mercury's evening appearance this month will not be as favourable as that of August this year, as Mercury will set before twilight ends.
Look out for the Leonid meteor shower, which peaks around the 17th of the month, when the Earth passes through the trail of dust and debris left behind by the comet Temple-Tuttle. Whilst normally a reliable but fairly quiet meteor shower, observers have noticed that roughly every 33 years the number of meteors observed during the shower show a marked increase as the Earth passes through the denser parts of the cometary debris trail.
Sadly, the 2016 shower is not expected to reach these high levels, with a predicted maximum of around 10-20 meteors per hour, and with a bright 18 day old Moon in the sky, there will be significant interference to hamper our viewing.
The radiant of the shower, from which the meteors appear to originate, is located in the constellation of Leo, which rises only a couple of hours before the Sun in our morning sky. The best time to observe the Leonids is about 2-3 hours before sunrise on the mornings around the peak.
Wishing you clear skies from the team here at Space Place at Carter Observatory.
Odds and Ends
George was targets for two different fraudulent or questionable schemes a couple of months ago. First, George was targeted by people who phoned him about his hotel reservation for the Half a Decade of ALMA conference he attended back in September. In this scheme, the callers claimed that people attending the conference needed to cancel their reservations at the conference hotel and re-book through them to get discounted rates. After doing this, the schemers keep the money, and the attendees are left without hotel reservations. Since George had a reservation at a different hotel, he did not fall for it. In the second questionable scheme, George was approach by an obscure publication claiming that they were interested in writing a two-page article about his press release back in July. Publications that use this approach sometimes charge high fees, but because the publications are hardly read by anyone, it is wasted money. George was uncertain if the publication that approached him was going to charge him this much, but he did not want to take the risk.
The hypothetical Planet Nine has once again appeared in the news; this time, it's being invoked to explain the apparent tilt of the Sun relative to the plane of its orbiting planets. The existence of a possible giant planet beyond Neptune is not a new idea, having persisted in one form or another since the 1830s. However, with the hypothesis now explaining both the clustering of Kuiper Belt object (KBO) orbits and the apparent stellar tilt, indirect evidence for its existence seems to be growing. Whether this will eventually be conclusively proven with a detection remains to be seen.
In today's show I compare the stances of the Clinton and Trump presidential campaigns on NASA and space exploration. You can read some of my source material here!
A team of French astronomers led by Pierre Kervella of the CNRS/Universidad de Chile have predicted a very rare gravitational lensing event, set to occur in 2028 using both new and archive data obtained with a range of ESO telescopes. This event will provide an ideal opportunity to look for evidence of a planet around a nearby star. By predicting the trajectories of the fast-moving stellar duo the Alpha Centauri A and B, with negligible error, it provides a unique opportunity for planet hunting in the Alpha Centauri system, by allowing us to search for secondary gravitational lensing events.
One of the most exciting alignments predicted by this study is between the more massive star in the Alpha Centauri pair, named Alpha Centauri A, and a distant background star - probably a red giant - nicknamed S5. In May 2028, there is a strong chance that the light from S5 will create an Einstein ring around Alpha Centauri A, observable with ESO's telescopes . This would provide a unique opportunity to look for planetary or low-mass objects in our nearest star system.
|Interview:||Dr. Laura Spitler and Charlie Walker|
|Night sky:||Ian Morison and Claire Bretherton|
|Presenters:||George Bendo, Naomi Asabre Frimpong, Fiona Healey and Jake Morgan|
|Editors:||Benjamin Shaw, Claire Bretherton, Xiaojin Liu, Jake Morgan and Charlie Walker|
|Segment Voice:||Iain McDonald|
|Website:||Parvin Mansour, Charlie Walker and Stuart Lowe|
|Producer:||Parvin Mansour and Charlie Walker|
|Cover art:||Model of Schiaparelli, Lander of ExoMars Trace Gas Orbiter Projekt 2016, seen at ESOC in Darmstadt, Germany CREDIT: Wikimedia Commons|