* Astronomy

Observations of Near Earth Asteroid 2010 AL30 on Jan. 13, 2010 (UTC)

On Jan. 11, 2010 the Linear Automated Sky Survey System identified AL30 as an incoming Near Earth Asteroid (NEO).  Over the next 12-24 hours, various observers improved the orbit determination, and the Harvard Minor Planet Centre (MPC) began putting out revised ephemeris and elements.  Closest approach was estimated to take place on Jan. 13 at approximately 0.34 the distance to the moon when the speed relative to the stars was estimated to be 10a-s/sec at magnitude of about 14-15.  The ephemeris showed that on the evening of Tues Jan 12 AL30 would be well placed in the Eastern sky for observers on the Atlantic coast in the U.S.
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There was speculation that the object could be a manmade rocket stage from an earlier planetary mission, possibly to Venus.
But Nasa's Jet Propulsion Laboratory (JPL) says that the object's observed orbit "actually makes it very unlikely that 2010 AL30 is a rocket stage".
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Ed ~ indeed, the close approach data for the Venus and earth encounters suggest the approaches were too large.

Earth    4th January, 2005         0.24  AU
Earth    7th January, 2006         0.15  AU
Venus   25th February, 2006     0.011 AU

The Venus exploration mission was launched in November 2005, and arrived at Venus in April 2006

Radar Astrometry

Object	Epoch (UT)	Measurement	Sigma	Units	freq	rcvr	xmit	bp	ref	Observer(s)	Notes	M
(2010 AL30)	2010-01-13 04:30:00	522184.314	1.	Hz	8560	-13	-14	C		BROZOVIC,Benner,L.	Correction of +1.5 Hz to s16 from CW echoes w/1 Hz res'n. Echo is ~6 Hz wide.
(2010 AL30)	2010-01-13 03:00:00	540757.660	1.	Hz	8560	-13	-14	C		BROZOVIC,Benner,L.	Correction of -19 Hz to s14 from CW echoes w/1 Hz res'n. Echo is ~8 Hz wide.

Source

Numerical backwards propagation of the orbital state of object 2010 AL30, as determined in January 2010, turns out to appear to lead to a close Venus encounter in spring 2006 and an Earth encounter in late 2005. These epochs are consistent with the Venus arrival and Earth launch dates, respectively, of ESA's Venus Express probe.
From the known approach conditions of Venus Express to Venus one can derive that a target point close above the planet's north pole, as was chosen in that mission, would lead to a deflection of an inert body on the same trajectory, such as the spent Fregat stage, that has a period of 1 year with perihelion and aphelion distances of 0.7 and 1.3 AU, respectively. These orbital parameters closely coincide with those of object 2010 AL30.
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