PN04/38: DECEMBER SPACE DIGEST
This release contains a summary of some significant astronomical and space events that will be taking place during December. It has been written in order to assist the media in planning and researching future stories related to space science and astronomy, particularly those with UK involvement. It is not intended to be fully comprehensive. Dates and times may be subject to change.
7 - 17 DECEMBER: GEMINID METEORS
The Geminid meteor shower is regarded as one of the best showers of the year, with an average of 80 shooting stars per hour at peak time. As a bonus this year, the peak on 13-14 December nearly coincides with the new moon on 12 December, promising dark skies for optimal viewing. Beginning on December 7 and lasting through December 17, the Geminids appear to emanate from a point in the constellation Gemini, near the bright stars Castor and Pollux. The shower radiant (the point from which the meteors seem to emanate) is above the horizon in the UK throughout the hours of darkness, but is highest in the sky around 01:00.
Compared to other meteors, the Geminids streak across the sky rapidly and appear fairly bright. However, the most unique aspect of the Geminid meteor shower is its origin. While most meteor showers come as a result of Earth sailing through a stream of debris left by comets, the Geminids come from a debris trail left by an asteroid known as 3200 Phaethon. Astronomers believe that the asteroid is the remnant of a comet that passed near the Sun so many times that all of its ice evaporated, creating the detritus that causes December's annual meteor shower.
10 DECEMBER: RAS MEETINGS, BURLINGTON HOUSE, PICCADILLY, LONDON W1, 10:30-15:30
PARALLEL MEETING 1) THE SCIENTIFIC AND SOCIAL CASE FOR HUMAN SPACEFLIGHT
(Linnean Society Lecture Theatre, Burlington House)
On Friday 10 December, an RAS Discussion Meeting will take place with the theme "The Scientific and Social Case for Human Spaceflight". The internationally renowned speakers will cover many aspects of the scientific, medical, social, educational, technological, inspirational, economic and political benefits of human space flight. The outline programme is as follows:
The meeting will examine the currently contentious question as to whether or not human knowledge will benefit from proposed future human space missions to the Moon and Mars. Specifically, the meeting will consider the potential scientific benefits of astronauts acting as field geologists on planetary surfaces, the benefits of a human spaceflight infrastructure for the maintenance of space-based astronomical and geophysical instruments, and the potential benefits to the medical, life, and materials sciences from research conducted in the space environment. The meeting will also consider some of the potential cultural benefits arising from human space exploration, especially its value as a means of stimulating public interest in science and technology, and in attracting young people into science.
PARALLEL MEETING 2) GRAVITATIONAL LENSING (JOINT RAS/IOP MEETING)
(Geological Society Lecture Theatre, Burlington House)
Gravitational lensing occurs when a massive object, such as a galaxy, magnifies the image of more distant objects in the same line of sight. Over the last few years, lensing has become one of the major probes used in cosmology. On the scale of galaxy clusters, lensing is helping us to understand the nature of dark matter, as well as revealing the environment in which galaxies form. On larger scales the statistics of the cosmic lensing shear signal are being used to pin down the cosmological parameters, the nature of the dark matter, and the relationship between galaxies and dark matter.
Speakers at this meeting will describe the background cosmological model and dark matter, lay out the basics of gravitational theory and methods, and describe how these are used to explore dark matter, dark energy and galaxy formation.
MONTHLY A&G (ORDINARY) MEETING, 16:00 - 18.00
(GEOLOGICAL SOCIETY LECTURE THEATRE, BURLINGTON HOUSE)
The 2003 RAS-Blackwell Prize will be presented to Dr. Clare Watt (Alberta). Talks will include:
FURTHER INFORMATION: RAS Meeting announcement - The Scientific Frontier as Observed by the NASA Rovers, Spirit and Opportunity: A New Mars
13 DECEMBER: "SOME UNIVERSES I HAVE KNOWN" - THE MCCREA CENTENARY LECTURE, UNIVERSITY OF SUSSEX.
Professor Sir William ('Bill') McCrea - the founder of the Astronomy Centre at the University of Sussex - would have reached the age of 100 this year. To commemorate the centenary of his birth, the University of Sussex is holding a Centenary Lecture at 6.30 pm on Monday 13 December 2004 (the actual birthday), preceded by a wine and nibbles reception at 5.30 pm.
The lecture, entitled "Some Universes I have Known", will be given by the well-known cosmologist, Professor John Barrow, who is also the author of popular science books such as Pi in the Sky, The Artful Universe, and The Book of Nothing.
Dr. John Gribbin, science writer and visiting fellow in astronomy at Sussex, will give a short appreciation of Sir William McCrea before the lecture.
The venue for the lecture and reception will be the Brighton and Sussex Medical School foyer and lecture theatre, in the building marked as 'Medical School Teaching Building'.
The lecture abstract reads: "Einstein showed us how to find descriptions of entire universes. We will look at some of the unusual universes that have been discovered by cosmologists over the last 90 years and introduce some of the weird properties they can possess. And we shall see whether any of them look like our own Universe."
Since Prof. McCrea was closely involved in the starting of the MSc programme, the University also invites donations to a Centenary Fund, which will be used to fund an annual Prize for the best MSc student in Astronomy or Cosmology at Sussex.
WEB SITE: http://www.sussex.ac.uk/USIS/news/
13 DECEMBER: CASSINI'S SECOND CLOSE TITAN FLYBY
Following its intriguing initial observations of Saturn's giant moon Titan on 26 October, the Cassini spacecraft is returning for another close look on 13 December. During this "Titan B" encounter, the spacecraft will fly past the smog-shrouded satellite at an altitude of almost 2,400 km (1,490 ml), or twice that of Titan A."
The Titan A close approach resulted in infrared and radar images that were able to observe unusual dark and light features beneath the orange haze. However, the nature of Titan's surface remains a mystery - one that will hopefully be solved when Europe's Huygens probe parachutes into Titan�s atmosphere on 14 January 2005. Huygens is scheduled to separate from Cassini on 25 December (see below).
UK scientists are playing significant roles in the Cassini mission with involvement in 6 of the 12 instruments on the orbiter. The UK�s Imperial College has the lead role in the magnetometer instrument on Cassini.
NASA Cassini Web site: http://saturn.jpl.nasa.gov/home/index.cfm
ESA Saturn Web site: http://www.esa.int/SPECIALS/Cassini-Huygens/index.html
25 DECEMBER: HUYGENS HEADS FOR TITAN
After more than seven years of piggybacking a ride on NASA's Cassini spacecraft, the European Space Agency's Huygens probe will separate from the mother craft on 25 December (approx. 02:00 GMT). Over the next three weeks it will make its own way towards Titan, Saturn's largest satellite and the second largest moon in the solar system.
Arrival is scheduled for 14 January 2005, when Huygens will plunge into Titan's dense atmosphere and spend about two hours parachuting toward the moon's mysterious surface. No one knows whether it will splash down in a sea of petrol-like hydrocarbons, or collide with rock-hard ice, possibly coated with a tarry, organic compounds.
Titan was first seen by Dutch astronomer Christiaan Huygens (after which the probe is named) in 1655. Not only is Titan the largest of Saturn's satellites, it is also larger than the planets Mercury and Pluto. It is the only satellite in the solar system with an appreciable atmosphere, mostly nitrogen, but also containing methane and ethane.
Titan's surface temperature is about 95 K (-178 degrees C) and surface air pressure is 1.5 times that on Earth. At this temperature and pressure, many simple chemicals that are present in abundance (methane, ethane, water, ammonia) can exist in solid, liquid and gaseous form. Rain, rivers, lakes and ice volcanism are all possible.
Titan orbits Saturn at a distance of just over 20 Saturn radii (1,222,000 km or 759,000 miles) which is far enough to carry the moon in and out of Saturn's magnetosphere. Very little is known about Titan's interior structure, including whether it has its own magnetic field and a subsurface ocean.
Titan's surface has been extremely difficult to study, as it is veiled by a dense hydrocarbon haze that forms in the dense stratosphere as methane is destroyed by sunlight. From the data collected so far, dark features can be seen crossing the equatorial region of Titan, with a large bright "continent" near longitude 90 degrees, now named Xanadu.
UK scientists are playing significant roles in the mission, with involvement in 2 of the 6 instruments on the Huygens probe. The UK's Open University has the lead role in the Surface Science Package on Huygens.
ESA Saturn-Titan Web site: http://www.esa.int/SPECIALS/Cassini-Huygens/index.html
ESA Huygens Web site: http://sci.esa.int/huygens
Date: 30th November 2004
Issued by Peter Bond, RAS Communications Officer.