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heads up for the perseids

The annual light-show of the Perseids, debris from the tail of Comet Swift-Tuttle, will be at its peak very soon: 12 August. The maximum rate of falling bits will be at 11h UT. It can be seen from latitudes about 62°N to about 32°S.

The show is expected to be particularly good for two reasons.

Firstly , the Earth is passing particularly close to the comet tail. The next time this will happen will be in 2028. For technical details.

Secondly, the moon is on the wane (looking smaller) so will not spoil the show with lots of moonlight as happened last year.

For USA-oriented information
For Europe-oriented information
Western Europe will have the best show, peaking somewhat after midnight, very early Thursday morning.

the web address for the article above is
https://www.abelard.org/news/science0408.php#perseids

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messenger probe sent on hot research

NASA has just launched the seventh mission in its “Discovery Program of lower cost, highly focused planetary science investigations”.

the journey

Launched on a Delta II 7925-H (heavy lift) launch vehicle, the largest allowed for NASA Discovery missions, the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft is going on

“a 4.9-billion mile (7.9-billion kilometer) journey that includes 15 loops around the Sun. The solar-powered MESSENGER will fly past Earth once, Venus twice and Mercury three times before easing into orbit around its target planet. The Earth flyby, a year after launch, and the Venus flybys, in October 2006 and June 2007, use the pull of the planets’ gravity to guide MESSENGER toward Mercury’s orbit. The Mercury flybys in January 2008, October 2008 and September 2009 fine-tune and slow MESSENGER’s track while allowing the spacecraft to gather data critical to planning the mission’s orbit.”

the payload

The seven scientific instruments that Messenger carries will enable it to “image all of Mercury for the first time, as well as gather data on the composition and structure of Mercury’s crust, its geologic history, the nature of its active magnetosphere and thin atmosphere, and the makeup of its core and the materials near its poles.”

the sun’s heat

“Mercury’s elongated orbit swings the planet to within 46 million kilometers (29 million miles) of the Sun, or about two-thirds closer to the Sun than Earth. The Sun also shines up to 11 times brighter at Mercury than we see from our own [planet]. Equator temperatures can reach 450°C or 840°F. However, Messenger “will only spend about 25 minutes of each 12-hour orbit crossing Mercury’s broiling surface at low altitude, and the combination of the sunshade, thermal blanketing and heat-radiation system allows the spacecraft to operate without special high-temperature electronics.”

the questions

Messenger will enable the resolution of questions unanswered since Mariner 10 made three flypasts in 1974 and 1975. The questions, which have been waiting for technology and mission design to advance sufficiently, include:

• Why is Mercury – the densest planet in the solar system – mostly made of iron?
• Why is it the only inner planet besides Earth with a global magnetic field?
• How can the planet closest to the Sun, with daytime temperatures near 840 degrees Fahrenheit, have what appears to be ice in its polar craters?

Other key science questions to be answered using data from the various on-board scientific instruments:

• Why is Mercury so dense? (instruments 2, 3, 6, 7)
• What is Mercury’s geologic history? (instruments 1, 2, 3, 5)
• What is the structure of Mercury’s core? (instruments 4, 5, radio science experiments)
• What is the nature of Mercury’s magnetic field? (instruments 5, 7)
• What are the unusual materials at Mercury’s poles? (instruments 2, 7)
• What volitiles are important at Mercury? (instruments 2, 3, 7)

the cost

“Approximately $427 million (including spacecraft and instrument development, launch vehicle, mission operations and data).”

The above is a short precis from the Mission launch press kit (a 33-page pdf). The kit contains much more detailed information. Its contents:

• General Release
• Media Services Information
• Quick Facts
• Mercury at a Glance
• Why Mercury? The Science of MESSENGER
• Key Science Questions
• Mercury’s First Visitor: Mariner 10
• NASA Discovery Program
• Mission Overview
• The Spacecraft
• Science Payload
• Spacecraft Systems and Components
• Program/Project Management

the web address for the article above is
https://www.abelard.org/news/science0408.php#mercury

uk government committee recommends open access to science research

“Academic libraries are struggling to purchase subscriptions to all the journal titles needed by their users. This is due both to the high and increasing journal prices imposed by commercial publishers and the inadequacy of library budgets to meet the demands placed upon them by a system supporting an ever increasing volume of research. Whilst there are a number of measures that can be taken by publishers, libraries and academics to improve the provision of scientific publications, a Government strategy is urgently needed.

“This Report recommends that all UK higher education institutions establish institutional repositories on which their published output can be stored and from which it can be read, free of charge, online. It also recommends that Research Councils and other Government funders mandate their funded researchers to deposit a copy of all of their articles in this way. The Government will need to appoint a central body to oversee the implementation of the repositories; to help with networking; and to ensure compliance with the technical standards needed to provide maximum functionality. Set-up and running costs are relatively low, making institutional repositories a cost-effective way of improving access to scientific publications.”
—
“ The preservation of digital material is an expensive process that poses a significant technical challenge. This Report recommends that the British Library receives sufficient funding to enable it to carry out this work. It also recommends that work on new regulations for the legal deposit of non-print publications begins immediately. Failure to take these steps would result in a substantial breach in the intellectual record of the UK.”

Report index.

“Taken together, these political recommendations suggest an international consensus is growing in support of open access, said Michael B. Eisen, cofounder of open-access publisher Public Library of Science.”

the web address for the article above is
https://www.abelard.org/news/science0408.php#science_research

email email_abelard [at] abelard.org

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