How will the philae lander contribute to scientist understanding of the solar system

B.it will provide information about the number of comets in the solar system

Mission

Rosetta made the most detailed study of a comet ever attempted. It followed the comet on its journey through the inner Solar System, measuring the increase in activity as the icy surface was warmed up by the Sun, and mapping its surface features and composition. The lander Philae took images and sampled the environment of its landing site  

What’s special?

Comets are considered the primitive building blocks of the Solar System, and likely helped ‘seed’ the Earth with water, and maybe even life. By studying the nature of the comet’s dust and gas, Rosetta will help scientists learn more about the role of comets in the evolution of the Solar System.  

Rosetta was the first mission ever to orbit a comet’s nucleus and land a probe on its surface. It was also  the first spacecraft to fly alongside a comet as it head towards the inner Solar System, watching how a frozen comet is transformed by the warmth of the Sun.  

Rosetta was the first space mission to journey beyond the main asteroid belt relying solely on solar cells for power generation, rather than the traditional radio-isotope thermal generators. The new solar-cell technology used on the orbiter's two giant solar panels allowed it to operate over 800 million kilometres from the Sun, where sunlight levels are only 4% of those on Earth.

quite an interesting way to teach topic sentences, because the answer to this question is the best definition of a topic sentence that one can present, it is as if answering the questions taught you how to do it, this is some real teaching, it is terribly well-done.

the topic sentence in this paragraph is:

topic sentences writers stay on track and keep a paragraph from becoming an aimless collection of sentences about an idea.

which incidentally tells you what a topic sentence should be.