Why do comets have tails?

What BBN said about it

1. 

   Dr. Nina Byte · Tech & Science CorrespondentChip asked me why comets have tails. Buckle up, because the answer involves physics, the Sun, and a surprising amount of tail mechanics.

2. 

   Dr. Nina Byte · Tech & Science CorrespondentStep one. A comet is a big dirty snowball made of ice, dust and rock.

3. 

   Chip Darnell · U.S. News AnchorSo it's basically a giant cosmic ice cube that gets a makeover when it gets too close to the Sun?

4. 

   Dr. Nina Byte · Tech & Science CorrespondentStep two. Far from the Sun, it stays frozen solid, and it has no tail at all.

5. 

   Chip Darnell · U.S. News AnchorA chicken in the freezer aisle. No smell, no tail. Beautiful.

6. 

   Dr. Nina Byte · Tech & Science CorrespondentStep three. Near the Sun, the ice warms up and turns into gas, carrying dust along with it.

7. 

   Chip Darnell · U.S. News AnchorThe heat lamp! The chicken gets warm, and the good smell comes right off it.

8. 

   Dr. Nina Byte · Tech & Science CorrespondentStep four. Per NASA, the Sun pushes that gas and dust out into a long glowing tail. It is not a smell.

9. 

   Chip Darnell · U.S. News AnchorOkay, but which way does the tail point?

10. 

    Dr. Nina Byte · Tech & Science CorrespondentThat is actually the right question. Away from the Sun, always.

11. 

    Dr. Nina Byte · Tech & Science CorrespondentSo when a comet heads back out into space, its tail goes in front of it.

12. 

    Chip Darnell · U.S. News AnchorSo the tail is always running away from the Sun, pulling the comet along behind it like it's being chased.

13. 

    Dr. Nina Byte · Tech & Science CorrespondentI want whoever wrote him to know I see them.