In eclipsing binary, the eclipsed object becomes dimmer. But why microlensing, which essentially is an object being occulted, causes the occulted object to brighten? (31.08.2004)

Does plate tectonics occur in Mars ? (28.01.2004)

The burning of the fuel requires oxygen, however, there is no air/oxygen in space? How can the problem be solved? (29.04.2003)

Can we use the Digital Camera to take the nebula's photo? (30.09.2002)

Why theoretically the images produced by a reflector is not as sharp as that by a refractor of same diameter of aperture? (30.09.2002)

What is microlensing? (13.05.2002)

When will the 9 planets stand in one straight line? (12.11.2001)

Is there a place where I can find the star chart(s) to show my kids the Chinese Star System -- the 28 Mansion, the 3 Enclosures, etc.? (08.10.2001)

Why the sun is red in colour ? (08.10.2001)

What does the Pluto look like? (09.07.2001)

Why stars have different colours? Some are blue and some are red. (18.06.2001)

I was told that the axle of the Earth changes over time (very slowly), is that truth? If so, how will the Earth be affected and what impacts will that bring to the living kinds on the planet? (14.05.2001)

When will the first person visited Mars ? (02.04.2001)

How many people had set foot on the Moon so far ? (02.04.2001)

What is wormhole ? (26.02.2001)

How long will it take for travelling from the Earth to the Sun? What is the distance between them ? (19.02.2001)

What is star ? (05.02.2001)

What is the difference between total solar eclipse and annular solar eclipse ? (05.02.2001)

When a spaceship is orbiting around the Earth, it is usually powered by the solar panel expanded. Can the spaceship be powered by nuclear energy instead of solar energy ? Also, there is gravitation force from the Earth to make it move around the Earth, then what is the use of solar energy ? Please reply.  (22.01.2001)

The sun is round ? (22.01.2001)