At larger distances the effect of this oblateness becomes negligible. "Icarus" is being studied to better understand general relativity, solar oblateness, and Yarkovsky drift. Explorer I gathered and transmitted data on atmospheric densities and the earth's oblateness. The nucleus is spherical in shape, showing no indication of oblateness. Other terms used are ellipticity, or oblateness. The oblateness of transiting exoplanets will affect the transit light curves. Geodetical observations from the expedition proved Earth's oblateness. Another (much less significant) effect is solar oblateness.