Kepler space telescope and Selenium tetrafluoride: Difference between pages

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Revision as of 11:21, 15 January 2007

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{{expert-subject|chemistry|date=january 2007}}

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{{importance|date=June 2006}}

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{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse;"

{{Spacecraft

! {{chembox header}} | Selenium tetrafluoride

| Name = Kepler Space Observatory

|-

| Image = [[Image:Keplerpacecraft.019e.jpg|350px]]

| align="center" colspan="2" | <!-- Unsourced image removed: [[Image:Selenium_tetrafluoride.jpg|200px|Selenium tetrafluoride]] -->

| Caption = Conceptual drawing of the Kepler Space Observatory

|-

| Organization = [[NASA]]

! {{chembox header}} | General

| Major_Contractors = ?

|-

| Mission_Type = Space telescope

| Other names

| Satellite_Of = [[Earth]]

|

| Launch = [[2007]]?

|-

| Launch_Vehicle = ?

| [[Chemical formula|Molecular formula]]

| Decay = ?

| SeF₄

| Mission_Duration = ?

|-

| Mass = ?

| [[Molar mass]]

| NSSDC_ID = ?

| 220.77 g/mol

| Webpage = [http://kepler.nasa.gov/ Kepler Home]

|-

| Semimajor_Axis = TBA

| Appearance

| Eccentricity = TBA

| white-yellow cubic crystals

| Inclination = TBA

|-

| Orbital_Period = TBA

| [[CAS registry number|CAS number]]

| Apogee = TBA

| [10026-03-6]

| Perigee = TBA

|-

| Orbits = TBA

! {{chembox header}} | Properties

}}

|-

| [[Density]] and [[Phase (matter)|phase]]

| 2.6 g/cm³, solid

|-

| [[Soluble|Solubility]]

| decomposes in [[water]] <br> insoluble in liquid [[bromine]] <br> decomposes in dry [[ammonia]]

|-

| [[Melting point]]

| 205°C, sublimes

|-

| [[Boiling point]]

| 288°C, decomposes

|-

! {{chembox header}} | '''Hazards'''

|-

| [[Directive 67/548/EEC|EU classification]]

| not listed

|-

| [[NFPA 704]]

| [[Image:nfpa_h4.png]][[Image:nfpa_f0.png]][[Image:nfpa_r0.png]]

|-

| {{chembox header}} | <small>Except where noted otherwise, data are given for<br> materials in their [[standard state|standard state (at 25 °C, 100 kPa)]]<br/>[[wikipedia:Chemical infobox|Infobox disclaimer and references]]</small>

|-

|}

'''Selenium tetrafluoride''' ([[Selenium|Se]][[Fluorine|F₄]]) is a [[chemical compound]].

'''Kepler Space Observatory''' (also known as '''''Kepler Space Telescope''''' or '''''Kepler Mission''''') is a space observatory planned by [[NASA]] that will search for [[extrasolar planet]]s. For this purpose, it will observe the brightness of about 100,000 [[star]]s over four years to detect periodical [[astronomical transit|transits]] of a star by one of its planets. Kepler will not be in an Earth orbit but in an Earth-trailing solar orbit so that Earth will not occult the stars which are to be observed and the photometer will not be influenced by stray light from Earth. The observatory is scheduled for launch in June [[2008]]; in January 2006, it was delayed eight months because of budget cuts and consolidation at NASA.

Conditions/substances to avoid are: [[heat]], [[flame]].

The probe is estimated to weigh 995 [[kg]], have a 0.95 [[meter]] [[photometer]], have a field of view of roughly two hands held at arm's length, will take un-focused "pictures" every three seconds, and will cost an estimated $467 million.

''The following is an extract from the [http://www.kepler.arc.nasa.gov/ official website] of the Kepler Space Observatory, detailing in summary its mission objectives:''

==External links==

The scientific objective of the Kepler Mission is to explore the structure and diversity of planetary systems. This is achieved by surveying a large sample of stars to:

{{ChemicalSources}}

* Determine how many terrestrial and larger planets there are in or near the habitable zone of a wide variety of spectral types of stars;

[[Category:Fluorides]]

* Determine the range of sizes and shapes of the orbits of these planets;

[[Category:Selenium compounds]]

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* Estimate how many planets there are in multiple-star systems;

* Determine the range of orbit size, brightness, size, mass and density of short-period giant planets;

{{inorganic-compound-stub}}

* Identify additional members of each discovered planetary system using other techniques; and

* Determine the properties of those stars that harbor planetary systems.

The probability of an Earthlike planet at 1 AU transiting its star is 0.47%, or about 1 in 210; it's slightly larger at 0.72 AU (the orbital distance of Venus), 0.65%; such planets would be Earthlike if the host star is a late G-type star such as [[Tau Ceti]]. In addition, because planets tend to orbit in similar planes, the possibility of multiple detections around a single star is actually rather high. For instance, if an alien Kepler-like mission observed Earth transiting the Sun, there is a 12% chance of also seeing Venus transit.

The Kepler mission has probably the best chance of detecting Earthlike planets at current technology levels. One important advantage it has is that it is designed to observe 100,000 stars simultaneously. This provides a much better chance for seeing a transit. In addition, the 1 in 210 probability means that if 100% of stars observed had Earthlike terrestrial planets, Kepler would find about 480 of them. The mission is therefore ideally suited to determine the frequency of Earthlike planets around other stars.

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==Other resources==

===See also===

* [[Spitzer Space Telescope]] (SST)

* [[Space Interferometry Mission]] (SIM)

* [[Terrestrial Planet Finder]] (TPF)

* [[Darwin (ESA)|Darwin]]

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===External links===

* [http://www.kepler.arc.nasa.gov/ Official website]

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[[Category:Discovery program]]

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