Thanks for verifying my result and catching my mistake. You're right, it's a volume of 10 x 10⁸ cubic meters, which is 10⁹. That's what I get for interweaving

Thanks for verifying my result and catching my mistake. You're right, it's a volume of 10 x 10⁸ cubic meters, which is 10⁹. That's what I get for interweaving a mantissa of 10 with scientific notation! Too late to edit now, but people should see this comment thread.