Prophets of doom can relax, at least for a while. The recently rediscovered
Comet Swift-Tuttle should safely miss the Earth on its next approach in
2126, says Brian Marsden of the Harvard Smithsonian Center for Astrophysics.
A collision on 14 August 2126 had been within the large margin of uncertainty
of earlier calculations. However, new studies have reduced the uncertainty,
and indicated that Swift-Tuttle may have been observed in 68 BC and 188
Marsden now says that the comet should make its closest approach to
the Sun in 2126 on 11 July, and cross the Earth’s orbit on 31 July – missing
the planet by 15 days. Calculations further into the future show ‘there
is very little possibility of the comet’s collision with the Earth during
the next millennium’, says Marsden. However, he adds that further observations
are important to verify the predictions.