女生小视频

The Supermoon rises over houses in Olvera, in the southern Spanish province of Cadiz, July 12, 2014. Occurring when a full moon or new moon coincides with the closest approach the moon makes to the Earth, the Supermoon results in a larger-than-usual appearance of the lunar disk. REUTERS/Jon Nazca (SPAIN - Tags: SOCIETY CITYSCAPE TPX IMAGES OF THE DAY) - GM1EA7D0FC401

When was it realised that moonlight is reflected sunlight? Part 2

One reader says Anaxagoras, born around 500 BC, wasn't the first to note that the moon is illuminated from the sun, with both Thales and Parmenides making the point earlier

How do dogs recognise that another animal is also a dog? Part 3

2K6A82T Artist's concept of astronauts and human habitats on Mars.

This week鈥檚 new questions

Why do fallen trees grow stems vertically from a horizontal trunk?

B1PP5G Spiral Galaxy M74 i. Image shot 2008. Exact date unknown.

What makes galaxies spin in a certain direction?

Various disco, soul and funk, seven inch records at second hand store.

Why can鈥檛 we conjure up smell and touch in our heads? Part 3

Yellow wash scrub sponge placed on wet blue background covered with drops of water in light room during household chores; Shutterstock ID 2167323189; purchase_order: -; job: -; client: -; other: -

This week鈥檚 new questions

Motion Speed Light in London City; Shutterstock ID 1093994570; purchase_order: -; job: -; client: -; other: -

Is the speed of light in high gravity different from in low gravity?

2REAK4A world map of african countries and arabian sea, madagascar island and zambia in close up focus

Why is the east coast of Madagascar so straight?

BNYGBG Astronaut Ed White the First American to Conduct a Spacewalk on Gemini 4 Mission June 3rd 1965 - Manuevering gun in his Right hand and Tether Cable

This week鈥檚 new questions

In films, people in space without a suit are depicted as being bodily intact and very cold. What would be the reality? And what is the shortest space a parked car can get out of? Or a parking car get into?

Are we conscious when we are asleep?

Could we build a habitable dome on the surface of Venus? (continued)

This week鈥檚 new questions

When was it first realised that moonlight must be reflected sunlight?