Editing 253 Mathilde (section)

{{Short description|Asteroid}}
{{Use dmy dates|date=October 2019}}
{{Good article}}
{{Infobox planet
| minorplanet=yes
| background=#D6D6D5
| name=253 Mathilde
| image=(253) mathilde crop.jpg
| image_scale =
| caption={{longitem|253 Mathilde as seen by [[NEAR Shoemaker|NEAR]] in 1997|style=padding: 4px 0;}}
| discovery_ref=<ref name="moore" />
| discoverer=[[Johann Palisa|J. Palisa]]
| discovery_site = [[Vienna Observatory|Vienna Obs.]]
| discovered=12 November 1885
| mpc_name=(253) Mathilde
| alt_names=A885 VA, 1915 TN<br/>{{mp|1949 OL|1}}
| pronounced={{IPAc-en|m|ə|ˈ|t|ɪ|l|d|ə}}
| named_after=Mathilde Loewy
| mp_category=[[Asteroid belt|Main belt]]
| epoch=31 July 2016 ([[Julian day|JD]] 2457600.5)
| orbit_ref=<ref name="jpl">Unless otherwise noted, parameters are per: {{cite web
  | last=Yeomans | first=Donald K. | date=August 29, 2003
  | url=https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=253
  | title=253 Mathilde
  | work=JPL Small-Body Database Browser
  | publisher=NASA | access-date=12 May 2016 }}</ref>
| aphelion={{Convert|3.35003411|AU|Gm|abbr=on|lk=on}}
| perihelion={{Convert|1.9467702|AU|Gm|abbr=on}}
| semimajor={{Convert|2.648402147|AU|Gm|abbr=on}}
| eccentricity=0.26492652
| period=4.31 [[Julian year (astronomy)|yr]] (1574.3 [[Julian year (astronomy)|d]])
| mean_anomaly=170.584348[[Degree (angle)|°]]
| inclination=6.7427122°
| asc_node=179.58936°
| arg_peri=157.39642°
| avg_speed=17.98 km/s<ref>For semi-major axis ''a'', orbital period ''T'' and eccentricity ''e'', the average orbital speed is given by:
:<math>\begin{align}
v_o & = \frac{2\pi a}{T}\left[1-\frac{e^2}{4}-\frac{3e^4}{64} - \dots \right] \\
    & = 18.31\ \mbox{km/s} \left[ 1 - 0.0177 - 0.00008 - \cdots \right] \\
    & \approx 17.98\ \mbox {km/s} \\
\end{align}\!\,</math>
For the circumference of an ellipse, see:
{{cite book
 | author=H. St̀eocker
 | author2=J. Harris
 | date=1998
 | title=Handbook of Mathematics and Computational Science
 | pages=[https://archive.org/details/handbookofmathem00harr/page/386 386]
 | publisher=Springer
 | isbn=0-387-94746-9
 | url-access=registration
 | url=https://archive.org/details/handbookofmathem00harr/page/386
 }}</ref>
| dimensions=52.8 km<ref name="jpl"/><br />(66&times;48&times;46&nbsp;km<ref name="icarus140"/>)
| mass={{val|1.033|0.044|e=17|u=kg}}<ref name="Yeomans 1997"/>
| density=1.3 g/cm<sup>3</sup><ref name="Yeomans 1997"/>
| surface_grav={{Gr|1.033e-4|26.4|5}}&nbsp;m/s<sup>2</sup>
| escape_velocity=22.9&nbsp;m/s
| rotation={{Convert|417.7|h|d|abbr=on|lk=on}}<ref name="jpl"/><br />17.406 ± 0.010&nbsp;d<ref>{{cite journal
  | author=Stefano Mottola | title=The slow rotation of 253 Mathilde
  | journal=Planetary and Space Science
  | date=1995 | volume=43 | issue=12 | pages=1609–1613
  | bibcode=1995P&SS...43.1609M
  | doi=10.1016/0032-0633(95)00127-1 |display-authors=etal}}</ref><br />(17&nbsp;d 9&nbsp;h 45&nbsp;[[minute|min]])
| spectral_type=[[C-type asteroid|Cb]]<ref name="jpl"/>
| abs_magnitude=10.3<ref name="jpl"/>
| albedo={{val|0.0436|0.004}}<ref name="jpl"/>
| single_temperature=≈ 174<ref>For asteroid albedo ''α'', semimajor axis ''a'', [[solar luminosity]] ''<math>L_0</math>'', [[Stefan–Boltzmann constant]] ''σ'' and the asteroid's [[infrared]] emissivity ''ε'' (≈ 0.9), the approximate mean temperature ''T'' is given by:
:<math>\begin{align}
T & = \left ( \frac{(1 - \alpha) L_0}{\epsilon \sigma 16 \pi a^2} \right )^{\frac{1}{4}} \\
  & = \left ( \frac{(1 - 0.0436) (3.827 \times 10^{26}\ \mbox{W})} {0.9 (5.670 \times 10^{-8}\ \mbox{W/m}^2\mbox{K}^4) 16 \cdot 3.142 (3.959 \times 10^{11}\ \mbox{m})^2} \right )^{\frac{1}{4}} \\
  & = 173.7\ \mbox{K}
\end{align}</math>

See: {{cite book
 | author=Torrence V. Johnson
 | author2=Paul R. Weissman
 | author3=Lucy-Ann A. McFadden
 | date=2007
 | title=Encyclopedia of the Solar System
 | pages=[https://archive.org/details/encyclopediaofso0000unse_u6d1/page/294 294]
 | publisher=Elsevier
 | isbn=978-0-12-088589-3
 | url=https://archive.org/details/encyclopediaofso0000unse_u6d1/page/294
 }}</ref> [[kelvin|K]]

| mean_motion={{Deg2DMS|0.22868000|sup=ms}} / day
| observation_arc=130.38 yr (47622 d)
| uncertainty=0
| moid={{Convert|0.939032|AU|Gm|abbr=on}}
| jupiter_moid={{Convert|2.06073|AU|Gm|abbr=on}}
| tisserand=3.331
}}

'''253 Mathilde''' is an [[asteroid]] in the intermediate [[asteroid belt]], approximately 50 kilometers in diameter, that was discovered by Austrian astronomer [[Johann Palisa]] at [[Vienna Observatory]] on 12 November 1885. It has a relatively [[ellipse|elliptical]] [[orbit]] that requires more than four years to circle the Sun. This [[List of tumblers (small Solar System bodies)|tumbling]] asteroid has an unusually [[List of slow rotators (minor planets)|slow rate of rotation]], requiring 17.4 days to complete a 360° [[wikt:revolution|revolution]] about its axis. It is a primitive [[C-type asteroid]], which means the surface has a high proportion of [[carbon]]; giving it a dark surface that reflects only 4% of the light that falls on it.<ref name="flyby"/>

Mathilde was visited by the [[NEAR&nbsp;Shoemaker]] spacecraft during June 1997, on its way to asteroid [[433&nbsp;Eros]]. During the short flyby, the spacecraft imaged a hemisphere of the asteroid, revealing many large craters that had gouged out depressions in the surface. It was the first carbonaceous asteroid to be explored and, until [[21&nbsp;Lutetia]] was visited in 2010, it was the largest asteroid to be [[List of minor planets and comets visited by spacecraft|visited by a spacecraft]].