A rare interplanetary treat is in store for stargazers in early June.
A transit of Venus, the rarest of astronomical phenomena in which the planet Venus passes across the face of the sun, will occur from June 5 to 6.
"The transit or passage of a planet across the face of the sun is a relatively rare occurrence… Transits of Venus occur in pairs with more than a century separating each pair," wrote Fred Espenak on the United States National Aeronautics and Space Administration (Nasa) website.
The first of this century's pair of transits occurred on June 8, 2004. After 2012, the next pair of transits will be in December 2117 and December 2125.
A Venus transit takes place when the planet Venus passes directly between the sun and the earth, becoming visible against the solar disk.
During a transit, Venus can be seen from Earth as a small black disk moving across the face of the sun.
The duration of such transits is usually measured in hours (the transit of 2004 lasted six hours).
A transit is similar to a solar eclipse of the moon.