The reaction energies of Ne21(d,α)F19 and Ne21(d,p)Ne22 from magnetic analysis

Separated isotopic targets of Ne21, which were produced at the Nobel Institute of Physics, have been used to measure the Q-values of the reactions (1) Ne21(d,α)F19, and (2) Ne21(d,p)Ne22. A double focusing magnetic spectrograph was used to compare the energy of the protons and alpha-particles from these reactions with the alpha-particles from ThC and ThC′. The angle of observation and the deuteron bombarding energy were chosen so that the particles being studied and the alpha-line used for energy calibration lay nearly side by side on the photographic plate used as a detector. The Q-values measured are 6.432±0.010 MeV for reaction (1) and 8.137±0.011 Mev for reaction (2). From these Q-values and the mass of F19 the atomic masses of Ne21 and Ne22 are obtained. Other alpha-groups from reaction (1) correspond to transitions to states in F19 at 0.113±0.008 Mev and 0.192±0.012 Mev above the ground state. Additional particle groups from N and Na contamination on the targets have been observed: The Q-values measured are 8.613±0.011 Mev for N14(d,p)N15 and 4.723±0.008 for Na23(d,p)Na24

Natural Transfer of Viable Microbes in Space from Planets in the Extra-Solar Systems to a Planet in our Solar System and Vice-Versa

We investigate whether it is possible that viable microbes could have been transported to Earth from the planets in extra-solar systems by means of natural vehicles such as ejecta expelled by comet or asteroid impacts on such planets. The probabilities of close encounters with other solar systems are taken into account as well as the limitations of bacterial survival times inside ejecta in space, caused by radiation and DNA decay. The conclusion is that no potentially DNA/RNA life-carrying ejecta from another solar system in the general Galactic star field landed on Earth before life already existed on Earth, not even if microbial survival time in space is as long as tens of millions of years. However, if the Sun formed initially as a part of a star cluster, as is commonly assumed, we cannot rule out the possibility of transfer of life from one of the sister systems to us. Likewise, there is a possibility that some extra-solar planets carry life that originated in our solar system. It will be of great interest to identify the members of the Sun's birth cluster of stars and study them for evidence for planets and life on the planets. The former step may be accomplished by the GAIA mission, the latter step by the SIM and DARWIN missions. Therefore it may not be too long until we have experimental knowledge on the question whether the natural transfer of life from one solar system to another has actually taken place.Comment: 25 pages, 1 table, accepted to Ap