  Measurements in the atmosphere and at the surface of Venus are required to
understand fundamental processes of how terrestrial planets evolve and how they
work today. While the European Venus community is unified in its support of the
EnVision orbiter proposal for the M5 opportunity, many scientific questions
also require in situ Venus exploration. ESA has already explored Venus entry /
descent probe science in its Planetary Entry Probe (PEP) study [ESA PEP study,
2010], and Venus balloon science in its Venus Entry Probe Study [ESA VEP study,
2005]; Venus balloons were also explored in detail by the European Venus
Explorer (EVE) M1/M2 and M3 proposals [Chassefiere et al., 2009; Wilson et al.,
2012]. While those in situ mission concepts remain scientifically compelling
and technically feasible, the present call requests new scientific concepts.
Therefore, in the present document, we suggest a long-duration lander at Venus,
which would be capable of undertaking a seismometry mission, operating in the
460{\deg}C surface conditions of Venus.
