Kohno et al. report the discovery of two CO (carbon monoxide) clouds which appear to be falling into the Galactic plane at more than 35 km/s. Data from the Mopra Southern Galactic Plane CO Survey reveals the clouds show head-tail distributions, elongated perpendicular to the Galactic plane. The team derive the distance of the clouds to be ~2.5 kpc based on Gaia Data Release 3. The CO clouds have molecular masses of ~4,000 solar masses and show kinetic temperatures of 30~50 K. The temperature in the heads of the clouds is significantly higher than the 10 K of typical molecular clouds, although no radiative heat source is found inside or close to the clouds. Based on these results, the team infer that the clouds are falling onto the Milky Way disk and are significantly heated by the strong shock interaction with HI (neutral hydrogen) gas in the disk. They suggest that the clouds represent part of the HI intermediate velocity clouds falling into the Galactic plane which were converted into molecular clouds by shock acompression. This is the first case of falling CO clouds having direct observed signatures of the falling motion including clear directivity and shock heating.