Dynamic Albedo of Neutrons
{{Infobox spacecraft instrument
| Name = Dynamic Albedo of Neutrons (DAN)
| Image = File:Dynamic Albedo of Neutrons.jpg
| Caption = DAN instrument on the Curiosity rover
| Operator = NASA
| Manufacturer = Russian Space Research Institute (IKI)
| Type = neutron spectrometer
| Function = hydrogen and H2O detector
| Mission_Duration = Primary: 668 sols (687 days)
Current: {{Curiosity Mission Timer}} sols ({{time interval|6 August 2012 05:17:57|show=d|disp=raw}} days) since landing
| Began = August 6, 2012
| Ceased =
| Webpage = {{url|https://msl-scicorner.jpl.nasa.gov/Instruments/DAN/}}
| Mass =
| Dimensions =
| Power_consumption =
| Resolution =
| Data_Rate =
| Spacecraft = Curiosity rover
| SC_Operator = NASA
| Launch = {{start-date|November 26, 2011, 15:02:00|timezone=yes}} UTC| Rocket =
| Launch_Site = Cape Canaveral LC-41
| COSPAR = 2011-070A
}}
The Dynamic Albedo of Neutrons (DAN) instrument is an experiment mounted on the Mars Science Laboratory{{'s}} Curiosity rover. It is a pulsed sealed-tube neutron source and detector used to measure hydrogen or ice and water at or near the Martian surface.{{cite journal |doi=10.1089/ast.2007.0157 |title=The Dynamic Albedo of Neutrons (DAN) Experiment for NASA's 2009 Mars Science Laboratory |year=2008 |last1=Litvak |first1=M. L. |last2=Mitrofanov |first2=I. G. |last3=Barmakov |first3=Yu. N. |last4=Behar |first4=A. |last5=Bitulev |first5=A. |last6=Bobrovnitsky |first6=Yu. |last7=Bogolubov |first7=E. P. |last8=Boynton |first8=W. V. |last9=Bragin |first9=S. I.| display-authors=5 |journal=Astrobiology |volume=8 |issue=3 |pages=605–12 |pmid=18598140 |bibcode=2008AsBio...8..605L}}{{cite web |url=http://msl-scicorner.jpl.nasa.gov/Instruments/DAN/ |archive-url=https://web.archive.org/web/20090320125107/http://msl-scicorner.jpl.nasa.gov/Instruments/DAN/ |url-status=dead |archive-date=March 20, 2009 |title=MSL Science Corner: Dynamic Albedo of Neutrons (DAN) |publisher=NASA/JPL |access-date=September 9, 2009}} The instrument consists of the detector element (DE) and a 14.1 MeV pulsing neutron generator (PNG). The die-away time of neutrons is measured by the DE after each neutron pulse from the PNG.
DAN was provided by the Russian Federal Space Agency, funded by Russia{{cite web |url=http://mars.jpl.nasa.gov/msl/mission/instruments/radiationdetectors/dan/ |title=Mars Science Laboratory: Mission |publisher=NASA/JPL |access-date=August 6, 2012}} and is under the leadership of Principal Investigator Igor Mitrofanov.{{cite web|url=https://mars.nasa.gov/news/1461/remaining-martian-atmosphere-still-dynamic/|title=Remaining Martian Atmosphere Still Dynamic|publisher=NASA|last=Webster|first=Guy|date=April 8, 2013|access-date=April 9, 2013}}
History
On August 18, 2012 (sol {{Curiosity Mission Timer|2012|08|18}}), DAN was turned on,{{cite news |url=http://www.cbsnews.com/news/curiositys-mars-travel-plans-tentatively-mapped/ |title=Curiosity's Mars travel plans tentatively mapped |work=CBS News |first=William |last=Harwood |date=August 18, 2012}} marking the success of a Russian-American collaboration on the surface of Mars and the first working Russian science instrument on the Martian surface since Mars 3 stopped transmitting over forty years ago.[https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1971-049A NSSDC – Mars 3] The instrument is designed to detect subsurface water.
On March 18, 2013 (sol {{Curiosity Mission Timer|2013|03|18}}), NASA reported evidence of mineral hydration, likely hydrated calcium sulfate, in several rock samples including the broken fragments of "Tintina" rock and "Sutton Inlier" rock as well as in veins and nodules in other rocks like "Knorr" rock and "Wernicke" rock.{{cite web |url=http://mars.jpl.nasa.gov/msl/news/whatsnew/index.cfm?FuseAction=ShowNews&NewsID=1446 |title=Curiosity Mars Rover Sees Trend In Water Presence |publisher=NASA |last1=Webster |first1=Guy |last2=Brown |first2=Dwayne |date=March 18, 2013 |access-date=March 20, 2013 |archive-url=https://web.archive.org/web/20130424111259/http://mars.jpl.nasa.gov/msl/news/whatsnew/index.cfm?FuseAction=ShowNews&NewsID=1446 |archive-date=April 24, 2013 |url-status=dead }}{{cite news |url=https://www.bbc.co.uk/news/science-environment-21340279 |title=Curiosity breaks rock to reveal dazzling white interior |work=BBC News |last=Rincon |first=Paul |date=March 19, 2013 |access-date=March 19, 2013}} Analysis using the rover's DAN instrument provided evidence of subsurface water, amounting to as much as 4% water content, down to a depth of {{convert|60|cm|ft|abbr=on}}, in the rover's traverse from the Bradbury Landing site to the Yellowknife Bay area in the Glenelg terrain.
{{multiple image|align=center|total_width=800
|header=Curiosity rover - How DAN works to detect water molecules - Actual Results|width1=1312 |height1=902 |image1=PIA16916-MarsCuriosityRover-DAN-1of2.jpg |caption1=No Water present |width2=1312 |height2=902 |image2=PIA16917-MarsCuriosityRover-DAN-2of2.jpg |caption2=Water present |width3=1440 |height3=1080 |image3=PIA16807-MarsCuriosityRover-DAN-Measurements-20130318.jpg |caption3=Actual Results - From Bradbury Landing to Glenelg (August 2012 - March 2013).
}}
File:PIA17762-MarsCuriosityRover-DAN-2M-Pulses-20140129.png
On August 19, 2015, NASA scientists reported that the DAN instrument on Curiosity detected an unusual hydrogen-rich area, at "Marias Pass," on Mars. The hydrogen found seemed related to water or hydroxyl ions in rocks within {{convert|3| feet}} beneath the rover, according to the scientists.{{cite web |author=Staff |title=PIA19809: Curiosity Finds Hydrogen-Rich Area of Mars Subsurface |url=http://photojournal.jpl.nasa.gov/catalog/PIA19809 |date=August 19, 2015 |work=NASA |access-date=August 19, 2015 }}
File:PIA19809-MarsCuriosityRover-HydrogenRichAreaFound-20150721.jpg
See also
References
{{Reflist|2}}
External links
- {{Commons category-inline|Dynamic Albedo of Neutrons}}
{{MSL}}
{{Satellite and spacecraft instruments}}
{{Mars}}
{{Portal bar|Solar System}}
Category:Mars Science Laboratory instruments
Category:Space program of Russia