Pluto has a density between that of rock and ice – so that immediately suggests the dwarf planet is made of a mix of both. But how do we know?
As we get older, there are many reasons our muscles might feel stiff. The most important thing is to keep moving.
No country can lay claim to sovereignty over a planet, moon or rocky body. But in the absence of clear laws regulating mining in space, it's a case of first in, best dressed for resource extraction.
Compared to Earth, more "oomph" is required to bring magma to the surface of Mars, and this is probably why we haven't seen any recent eruptions on the red planet.
If you fall one storey, dust yourself off – you'll be fine. If you fall seven storeys: sorry, but you've probably got about 2 seconds to prepare to meet your maker.
Many people have an appearance of dark circles on the lower eyelids, and they have many different causes.
Eggs are tiny wonders, but even wonders can go wonky sometimes. We look at everything from double-yolkers to eggs with no shell at all.
It's all about the chemistry. Adding lemon can enhance the flavour and enjoyment of tea, and change its colour, but its best not to expect any extra boosts to your health.
Whether or not masks can protect against invading or escaping bugs depends on the type of mask and material.
The internet conspiracists are half right: most lights we have inside do emit UV, but not enough to harm us.
The umbilical cord drops off a baby's belly button after birth. What happens on the inside is far more fascinating.
There are a few reasons why smartphones, tablets and PCs start to seem less snappy over time.
Chicken eyes are stranger than you think: they can look up and down at the same time.
A reader wants to know why our noses run just because it's cold.
Why is it the flu virus is so deadly compared to the common cold virus?