  The active broadband (1 kHz-100 MHz) tripole antenna now envisaged to be
placed on the European Lunar Lander located at the Lunar South Pole allows for
sensitive measurements of the exosphere and ionosphere, and their interaction
with the Earths magnetosphere, solar particles, wind and CMEs and studies of
radio communication on the moon, that are essential for future lunar human and
science exploration. In addition, the lunar South pole provides an excellent
opportunity for radio astronomy. Placing a single radio antenna in an eternally
dark crater or behind a mountain at the south (or north) pole would potentially
provide perfect shielding from man-made radio interference (RFI), absence of
ionospheric distortions, and high temperature and antenna gain stability that
allows detection of the 21 cm wave emission from pristine hydrogen formed after
the big bang and into the period where the first stars formed. A detection of
the 21 cm line from the moon at these frequencies would allow for the first
time a clue on the distribution and evolution on mass in the early universe
between the Epoch of Recombination and Epoch of Reionization (EoR). A single
lunar radio antenna would also allow for studies of the effect of solar flares
and Coronal Mass Ejections (CMEs) on the solar wind at distances close to earth
(space weather) and would open up the study of low frequency radio events from
planets such as Jupiter and Saturn, which are known to emit bright (kJy-MJy)
radio emission below 30 MHz (Jester & Falcke, 2009). Finally, a single radio
antenna on the lunar lander would pave the way for a future large lunar radio
interferometer; not only will it demonstrate the possibilities for lunar radio
science and open up the last unexplored radio regime, but it will also allow a
determination of the limitations of lunar radio science by measuring the local
radio background noise.
