Clumps (IMAGE) University of Manchester Caption A close-up of part of the nebula shows that the ring consists of large numbers of small clumps. The team counts as many as 20,000 clumps. They contain molecular hydrogen and are much cooler and denser than the rest of the nebula. Some of the clumps are beginning to develop tails (see, e.g., at the lower right), behaving as comets the size of planets. About half of all gas in the nebula is in these clumps. Credit The University of Manchester Usage Restrictions use credit License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.