This is the first measurement of the size.

It is now increasingly hard to justify calling Pluto a planet if UB313 is not also given this status.

There's good evidence that it's definitely larger, by quite a bit, than Pluto.

It would be impolite to Pluto to degrade it to something less.

Since UB313 is decidedly larger than Pluto, it is now increasingly hard to justify calling Pluto a planet if UB313 is not also given this status.

Since UB 313 is decidedly larger than Pluto, it is now increasingly hard to justify calling Pluto a planet if UB 313 is not also given this status.